Assessing North Atlantic winter climate response to geomagnetic activity and solar irradiance variability
Sign Up to like & getrecommendations! Published in 2019 at "Quarterly Journal of the Royal Meteorological Society"
DOI: 10.1002/qj.3657
Abstract: Recent studies suggest a response in the North Atlantic winter circulation which lags by a couple of years with respect to sunspot maximum. This has been explained by two different top‐down mechanisms: a solar wind… read more here.
Keywords: geomagnetic activity; atlantic winter; north atlantic; activity ... See more keywords
Lomb–Scargle periodogram analysis of the periods around 5.5 year and 11 year in the international sunspot numbers
Sign Up to like & getrecommendations! Published in 2018 at "Astrophysics and Space Science"
DOI: 10.1007/s10509-018-3332-z
Abstract: The New International Sunspot Numbers (NISNs) have been successfully compiled and can be downloaded from the World Data Center-Sunspot index and Long-term Solar Observations, Royal Observatory of Belgium, Brussels. The periods in these NISNs have… read more here.
Keywords: lomb scargle; year; international sunspot; scargle periodogram ... See more keywords
Probing the Sunspot Atmosphere with Three-Minute Oscillations
Sign Up to like & getrecommendations! Published in 2017 at "Solar Physics"
DOI: 10.1007/s11207-017-1222-0
Abstract: We present a seismological method for probing the solar atmosphere above sunspot umbrae with three-minute oscillations. Our technique allows us to estimate both the vertical distance between atmospheric layers and the wave-propagation speed, without specifying… read more here.
Keywords: minute oscillations; distance; speed; sunspot umbrae ... See more keywords
Christian Horrebow’s Sunspot Observations – II. Construction of a Record of Sunspot Positions
Sign Up to like & getrecommendations! Published in 2019 at "Solar Physics"
DOI: 10.1007/s11207-019-1466-y
Abstract: The number of spots on the surface of the Sun is one of the best tracers of solar variability we have. The sunspot number is not only known to change in phase with the 11-year… read more here.
Keywords: record sunspot; variability; sunspot; christian horrebow ... See more keywords
Unaided-eye Sunspot Observations in 1769 November: A Comparison of Graphical Records in the East and the West
Sign Up to like & getrecommendations! Published in 2019 at "Solar Physics"
DOI: 10.1007/s11207-019-1488-5
Abstract: Sunspots can be seen with the unaided eye when they are sufficiently large. Due to the known correlation between the occurrence of unaided-eye sunspot observations and the phase of the solar cycle, these observations frequently… read more here.
Keywords: 1769 november; unaided eye; eye sunspot; sunspot observations ... See more keywords
Sunspot Positions and Areas from Observations by Thomas Harriot
Sign Up to like & getrecommendations! Published in 2020 at "Solar Physics"
DOI: 10.1007/s11207-020-01604-4
Abstract: The reconstruction of sunspot parameters in the early era of telescopic observations extends our knowledge on visual sunspot activity up to 400 years into the past. 200 digital solar images from 18 December 1610 to… read more here.
Keywords: positions areas; thomas harriot; observations thomas; areas observations ... See more keywords
Long-Term Variations in Solar Activity: Predictions for Amplitude and North–South Asymmetry of Solar Cycle 25
Sign Up to like & getrecommendations! Published in 2022 at "Solar Physics"
DOI: 10.1007/s11207-022-01956-z
Abstract: In most of the solar cycles, activity in the northern and southern hemispheres peaks at different times. One hemisphere peaks well before the other and at least one of the hemispheric maxima frequently does not… read more here.
Keywords: sunspot; north south; cycle; activity ... See more keywords
Does Machine Learning reconstruct missing sunspots and forecast a new solar minimum?
Sign Up to like & getrecommendations! Published in 2021 at "Advances in Space Research"
DOI: 10.1016/j.asr.2021.03.023
Abstract: Abstract The retrodiction and prediction of solar activity are two closely-related problems in dynamo theory. We applied Machine Learning (ML) algorithms and analyses to the World Data Center’s newly constructed annual sunspot time series (1700-2019;… read more here.
Keywords: cycle; year; sunspot; missing sunspots ... See more keywords
North-South asymmetry of some solar parameters: A study based on the dominance of hemispheric sunspot activity during the solar cycles 18–24
Sign Up to like & getrecommendations! Published in 2021 at "Chinese Journal of Physics"
DOI: 10.1016/j.cjph.2021.02.007
Abstract: Abstract Solar activity indices differ over the solar disk, and different activity parameters are not considered to be symmetric between the northern and southern solar hemispheres. In the present paper, the daily data of a… read more here.
Keywords: cycle; dominance; solar cycles; activity ... See more keywords
Chinese sunspot drawings and their digitization – (III) quasi-biennial oscillation of the hand-drawn sunspot records
Sign Up to like & getrecommendations! Published in 2020 at "Research in Astronomy and Astrophysics"
DOI: 10.1088/1674-4527/20/11/190
Abstract: Quasi-biennial Oscillations (QBOs) of the Sun have a significant meaning as a benchmark of solar cycle, not only for understanding the dynamo action but also in terms of space weather prediction. In this paper, the… read more here.
Keywords: chinese sunspot; gnevyshev gap; cycle; hand ... See more keywords
Sunspot positions from observations by Flaugergues in the Dalton Minimum
Sign Up to like & getrecommendations! Published in 2023 at "Monthly Notices of the Royal Astronomical Society"
DOI: 10.1093/mnras/stad1489
Abstract: French astronomer Honoré Flaugergues compiled astronomical observations in a series of hand-written notebooks for 1782–1830, which are preserved at Paris Observatory. We reviewed these manuscripts and encoded the records that contain sunspot measurements into a… read more here.
Keywords: positions observations; sunspot positions; flaugergues dalton; dalton minimum ... See more keywords