Behavior Of Sun Research Articles

Study of X-ray spectral and timing properties of astronomical sources using low-cost stratospheric balloons

ABSTRACTAstronomical objects, such as the Sun, accreting matter around black holes, neutron stars, white dwarfs, etc. are known to emit X-rays and gamma-rays. Some of these sources, such as highly magnetized neutron stars, show periodic pulsations. Even accreting matter around black holes and neutron stars shows timing properties including quasi-periodic oscillations. In this paper, we use the data of low-cost, lightweight, high-altitude (∼42 km) small, stratospheric balloon-borne missions of the Indian Centre for Space Physics. We measure the intensity of the secondary cosmic rays, the radiation fluxes, and the spectra of persistent X-ray sources or transient events such as solar flares and gamma-ray bursts, apart from routine weather parameters. In this study, we present the source detection method without an onboard pointing system and the temporal and spectral behaviour of the quiet Sun. We also analyse the data containing Crab in the field of view to find the pulsation of the Crab pulsar. During the analysis of the source detection and spectrum of the solar X-rays, we calculate the detector’s background radiation (mainly secondary cosmic rays) using physical assumptions and also take care of the atmospheric absorption effects. Finally, we show the source detection processes for the strong sources such as the Sun, Crab, and Cyg X-1, obtaining the quiet Sun’s spectrum. Among the interesting timing properties, we present the result for the Crab pulsar and find the well-known ∼33 Hz pulsations whenever our instrument pointed to the Crab.

Stellar magnetic activity and the butterfly diagram of Kepler-63

Context. The study of young solar-type stars is fundamental for better understanding the magnetic activity of the Sun. Most commonly, this activity manifests itself in the form of spots and faculae. As a planet in transit crosses in front of its host star, a dark spot on the stellar surface may be occulted, causing a detectable variation in the light curve. Kepler-63 is a young solar-like star with an age of only 210 Myr that exhibits photometric variations compatible with spot signatures. Because the planet that orbits it is in an almost polar orbit, different latitudes of the star can be probed by the method of spot transit mapping. Aims. The goal of this work is to characterise the spots of Kepler-63 and thus decipher the behaviour of the young Sun. Because planetary orbit is highly oblique, the latitudinal distribution and thus the differential rotation of the spots may be determined. Methods. A total of 150 transits of Kepler-63b were observed in the short-cadence light curve, corresponding to a total duration of about four years. Each transit light curve was fit by a model that simulates planetary transits and allows including starspots on the surface of the host star. This enables the physical characterisation of the spot size, intensity, and location. We determined the spot position in a reference frame that rotates with the star, and thus obtained the latitudinal distribution of the spots. Results. We fit a total of 297 spots and determined their sizes, intensities, and positions. The longitude and latitude of the spots were calculated in a reference frame that rotated with the star. The latitude distribution of spots exhibits a bimodality with a lack of spots around 34°. Moreover, the spot sizes tend to be larger close to the equator, but decrease toward the latitude distribution gap, after which they again increase toward the poles. High-latitude spots dominate the magnetic cycle of Kepler-63. For a mean stellar rotation period of 5.400 d, 59 spots were found at approximately the same longitude and latitude on a later transit. Some of these spots were detected eight transits later. This shows that the lifetimes of spots can be at least 75 d. Conclusions. The geometry of the Kepler-63 system, enabled us to build a starspot butterfly diagram, similar to that of sunspots. It was also possible to infer the differential rotation of Kepler-63 from the spots at different latitudes. This star was found to rotate almost rigidly with a period of 5.400 d and a relative shear close to 0.01% for latitudes lower than 34°, whereas the high latitudes do not follow a well-behaved pattern.

The impact of ultraviolet photography on the sun safety awareness and behavior of skiers and snowboarders

Objective: Snow sport enthusiasts, such as snowboarders and skiers, are a less studied population at significant risk for ultraviolet(UV) exposure due to long hours spent at high altitudes with more intense UV radiation. Studies have documented the efficacy ofUV photography to impact sun protection habits by individuals with a range of skin cancer risk factors. Informing snow sportenthusiasts of their sun damage through UV photography may be a way to change this population’s perception and behavior of sun protection.Methods: A UV camera was utilized at the 2013 SnowSports Industries America Snow Show in Colorado to assess the levelof accumulated sun damage in show attendees. A follow-up survey was performed at this same event one year later in 2014. Participants at the 2013 event were recruited to a UV camera booth and completed a ten-question pre-survey assessing baselinesun-safety awareness and behaviors. Full-face frontal photographs using two different UV camera models were then takenand shown on a digital screen to the participants. Individualized education was provided regarding the degree of sun damage revealed by the intervention as well as sun safety recommendations. Participants were at the 2013 event were then contacted viaemail six months later to complete a ten-question survey on surveymonkey.com. The survey assessed the permanence of the UV photography intervention on sun habits over the duration of the ski/snowboard season. Email was used for communication purposes after a poor response rate using telephone for a one-month post-intervention follow-up.Results: The 2013 post-intervention study revealed a 41% response rate (n=46) with overall positive influence of UV photographyon sun protection behavior in the survey. Post-intervention survey results for the 2014 study with an observed response rate of 28% (n=37) with a similar overall positive influence of our intervention on sun protection behavior.Conclusions: UV photography-based interventions and education may impact sun-safety behavior in high-risk populations such as skiers and snowboarders that may otherwise not receive appropriate education regarding the dangers of UV exposure and prevention of skin cancer. However, more controlled studies should be conducted to positively associate UV photography intervention and education and sun safety behavior.

Tourist Spending Dynamics in the Algarve: A Cross-Sectional Analysis

This paper assesses the determinants of international tourists' spending in the Algarve from 2007 to 2010. Based on a sample of 15,542 observations a cross-section model was estimated using ordinary least squares. The results reveal that a combination of socio-demographic, behavioural and motivation variables explain the spending patterns of international tourists in the Algarve. Analysis of the data indicates that tourist motivations related to accommodation facilities, cultural and historical resources, gastronomy, hospitality, prices and sightseeing tours positively affect tourists' spending. Moreover, the findings provide evidence that, over the years, the most loyal markets in Algarve reveal changing patterns in their spending behaviour. Destination management authorities should be aware of this spending behaviour of second-generation sun and sand visitors and should formulate strategies accordingly. Policy and managerial recommendations are discussed.

Tourism demand and atmospheric parameters: non-intrusive observation techniques

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 51:135-145 (2012) - DOI: https://doi.org/10.3354/cr01068 Tourism demand and atmospheric parameters: non-intrusive observation techniques M. B. Gómez-Martín1,*, E. Martínez-Ibarra2 1Department of Physical Geography and Regional Geographical Analysis, University of Barcelona, Montalegre 6, Barcelona 08001, Spain 2Laboratory of Climatology, University of Alicante, Campus de San Vicente del Raspeig, s/n, Apdo. Correos 99, Alicante 03080, Spain *Email: bgomez@ub.edu ABSTRACT: In this study, we used images from webcam cameras and Argus video systems to examine how the behaviour of sun and beach tourists in Spain was influenced by the meteorological weather conditions. We applied a qualitative visual count method, which involved creating a bank of images and undertaking a classification of the density of use at each observation point. Thus, each image was assigned a density-of-use level. These results were then correlated with a range of meteorological variables and the physiological equivalent temperature (PET). Atmospheric conditions do have an impact on the behaviour of sun and beach tourists, and our study shows that the density of use of the beaches in Spain is controlled by solar radiation (the aesthetic facet) and the maximum temperature and PET (the comfort facet). The optimal thresholds of these meteorological variables for going to the beach were as follows: a maximum temperature between 28.83 and 31°C; a maximum PET between 34.5 and 38.8°C; a percentage of solar radiation at 13:00 h of at least 50%; a wind speed at 13:00 h of <8 m s−1 (or, at the most, <10 m s−1); and no rainfall or, at the most, <1 mm d−1 or a rainfall event with a duration of <60 min. The application of these thresholds for determining the degree of use of beaches during the year should lead to more accurate forecasts of the calendar of the tourist season and ensure that the basic tourist resources provided for beach tourism are managed more effectively during these periods, including the provision of services and safety facilities. KEY WORDS: Sun and beach tourism · Atmospheric conditions · Tourism demand · Webcams · Spain Full text in pdf format PreviousNextCite this article as: Gómez-Martín MB, Martínez-Ibarra E (2012) Tourism demand and atmospheric parameters: non-intrusive observation techniques. Clim Res 51:135-145. https://doi.org/10.3354/cr01068 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 51, No. 2. Online publication date: March 07, 2012 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2012 Inter-Research.

Les verbes préfixés en grec moderne

In the present article we are studying the relation between the prefix sun- and the simple verbal basis of the Greek lexicon-grammar in order to find the regularities pertaining to the behavior of the prefix sun-, which will contribute to the semi-automatic enrichment of the electronic dictionary DELAGR. A series of observations on the syntactic structures containing these verbs reveal the fact that prefixation has to be considered in terms of predicative relations and arguments. The article is divided in three parts: 1. presentation of some particularities; 2. description of the inflection of prefixed verbs 3. presentation of data and restraints. In conclusion we are providing some statistic elements concerning the formation of prefixed verbs with sun-.

Analyzing the variation of embedding dimension of solar and geomagnetic activity indices during geomagnetic storm time

Abstract Cyclic solar activity as one of the natural chaotic phenomena has significant effects on Earth, climate, and satellites. Rapid changes in the near-Earth space environment can affect the performance and reliability of both spacecraft and ground-based systems. This can imply major problems due to communication and satellite operational anomalies. Therefore, it is meaningful to analyze solar activity and geomagnetic indices to elicit the behavior of sun as the origin of most of these chaotic phenomena. One of the most important tools for analyzing the chaotic trends is the “Embedding Dimension” (ED). In this paper, the variation of ED for solar activity indices especially during storm time for two well-known storms is considered. The first storm is the super-storm on 13 March 1989, which shuts down the power supply system in Québec, Canada and the second one is the storm caused by Coronal Mass Ejection on 11 January 1997 which causes the failure of Telstar 401 satellite. The method of this paper is based on the fact that the reconstructed dynamics of an attractor should be a smooth map, i.e. with no self intersection in the reconstructed attractor. It is shown that the Embedding Dimension (and other chaotic characteristics) of some solar and geomagnetic activity indices during these storms varies rapidly.

Perceptions of the environmental impacts of tourism: A comparative study of the attitudes of German, Russian and Turkish tourists in Kemer, Antalya

This paper investigates perceptions of the environmental impacts of tourism in an area of mass tourism, Kemer, Antalya, in Turkey. The perceptions and behaviour of sun- and sea-seeking tourists of three different nationalities are evaluated: German, Russian and Turkish. Their willingness to pay and attitudes towards the bodies responsible for protecting the environment are also assessed. The research uses a questionnaire which was translated into three languages (German, Russian and Turkish) and was applied to a total of 460 tourists. The results confirmed that differences in 'environmental awareness' were more strongly associated with differences in nationality, than with educational levels and occupations. Above all, German tourists were more 'environmentally aware' than Russian and Turkish tourists. There were also national differences in tourists' 'willingness to pay' for environmental measures. The results pose important issues for tourism policy in respect of market segmentation and environmental outcomes.

6. Bishop’s Behavior of the Sun

6. Bishop’s Behavior of the Sun