Multiple-scale Temporal Variability of Climatic Time Series in the Western Region of Iran [PDF]
Sustainable Earth Trends, 2023 The current research aims to carry out a multi-timescale variability analysis for the time series of sunspots (SN), precipitation (Pr), and maximum temperature (Tmax) in four main stations in the western area of Iran.
Abolfazl Neyestani
doaj +1 more source
Invisible sunspots and rate of solar magnetic flux emergence [PDF]
, 2007 Aims. We study the visibility of sunspots and its influence on observed values of sunspot region parameters. Methods. We use Virtual Observatory tools provided by AstroGrid to analyse a sample of 6862 sunspot regions.
Bogdan +18 more
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Velocity fields in and around sunspots at the highest resolution [PDF]
, 2010 The flows in and around sunspots are rich in detail. Starting with the Evershed flow along low-lying flow channels, which are cospatial with the horizontal penumbral magnetic fields, Evershed clouds may continue this motion at the periphery of the ...
Carsten Denker +3 more
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Temporal variations of different solar activity indices through the solar cycles 21-23 [PDF]
Serbian Astronomical Journal, 2017 Here, we compare the sunspot counts and the number of sunspot groups (SGs) with variations of total solar irradiance (TSI), magnetic activity, Ca II K-flux, faculae and plage areas.
Gäoker Ü.D. +3 more
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Correlations between sunspots and their moat flows [PDF]
, 2013 Context. The presence of the moat flow around sunspots is intimately linked to the mere existence of sunspots. Aims. We characterize the moat flow (MF) and Evershed flow (EF) in sunspots to enhance our knowledge of sunspot structures and photospheric ...
Löhner-Böttcher, Johannes +1 more
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Detecting the Sun’s active region using image processing techniques
Physical Sciences and Technology, 2021 The term ‘space weather’ refers to adverse conditions on the Sun that could affect the structures of space or terrestrial technology and risk human health or life. Flares produce effects that span the electromagnetic spectrum.
A. Sarsembayeva +4 more
doaj
Automatic Recognition of Sunspots in HSOS Full-Disk Solar Images
, 2016 A procedure is introduced to recognise sunspots automatically in solar full-disk photosphere images obtained from Huairou Solar Observing Station, National Astronomical Observatories of China. The images are first pre-processed through Gaussian algorithm.
Deng, YuanYong +3 more
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On the Absence of Photospheric Net Currents in Vector Magnetograms of Sunspots Obtained From Hinode (SOT/SP) [PDF]
, 2009 Various theoretical and observational results have been reported regarding the presence/absence of net electric currents in the sunspots. The limited spatial resolution of the earlier observations perhaps obscured the conclusions.
Baty +21 more
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Bimodal Distribution of Magnetic Fields and Areas of Sunspots
, 2013 We applied automatic identification of sunspot umbrae and penumbrae to daily observations from the Helioseismic Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) to study their magnetic flux (B) and area (A).
Pevtsov, Alexei A., Tlatov, Andrey G.
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Helioseismic holography of simulated sunspots: magnetic and thermal contributions to travel times
, 2016 Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun.
Birch, A. C. +3 more
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