Results 131 to 140 of about 3,439,333 (263)

Anomalous low level of cosmic ray intensity decreases observed during 1980 [PDF]

Past studies have revealed solar cycle changes in the sunspot activity, as well as in many other solar parameters, such as, solar flares and solar coronal holes.
Agrawal, S. P., Jain, A. K., Pandey, P. K.   +2 more
core   +1 more source

Extraction of Sunspots from Chinese Sunspot Drawings Based on Semisupervised Learning

The Astrophysical Journal
China has six observing stations, providing over 52,000 handwritten sunspot drawings from 1947–2016. The observing stations are the Purple Mountain Astronomical Observatory (PMO), Yunnan Astronomical Observatory (YNAO), Qingdao Observatory Station (QDOS),
Qianqian Dong, Yunfei Yang, Song Feng, Wei Dai, Bo Liang, Jianping Xiong   +5 more
doaj   +1 more source

An Improved Prediction of Solar Cycles 25 and 26 Using the Informer Model: Gnevyshev Peaks and North–South Asymmetry

The Astrophysical Journal
Forecasting the amplitude and timing of the sunspot cycle is highly important for solar physics and space weather applications, but high-precision prediction of solar magnetic activity has remained an outstanding challenge.
Jie Cao, Tingting Xu, Linhua Deng, Xueliang Zhou, Shangxi Li, Yuxia Liu, Wenhua Wang, Weihong Zhou   +7 more
doaj   +1 more source

Role of Sunspot Latitude versus Tilt in Determining the Polar Field and Amplitude of the Next Cycle: Cause of the Weak Solar Cycle 20

The Astrophysical Journal
One prominent feature of the solar cycle is its irregular variation in its cycle strength, making it challenging to predict the amplitude of the next cycle.
Bidisha Dey, Anu Sreedevi, Bidya Binay Karak   +2 more
doaj   +1 more source

Statistics of sunspot group clusters

Journal of Space Weather and Space Climate, 2013
The Zubrzycki method is utilized to find all sunspot groups which are close to each other during each Carrington rotation. The sunspot group areas and their positions for the years 1874–2008 are used.
Getko Ryszarda
doaj   +1 more source

Participation Dynamics: Sunspots and Cycles

, 1990
This paper investigates the possibility of sunspots equilibria and endogenous cycles in an overlapping generations model with strategic interactions. We consider an economy with imperfectly competitive product markets. There is a participation decision on the part of prospective firms and a strategic complementarity emerges from the interaction of ...
Satyajit Chatterjee, Russell Cooper, B. Ravikumar   +2 more
openaire   +1 more source

Robustness of Solar-Cycle Empirical Rules Across Different Series Including an Updated Active-Day Fraction (ADF) Sunspot Group Series

, 2021
I. Usoskin, G. Kovaltsov, Wilma Kiviaho
semanticscholar   +1 more source

Low-latitude Sunspot Group Tilt Angles in 15–24 Activity Cycles

The Astrophysical Journal
An analysis of the tilt angles of the active regions in 15–24 activity cycles was performed. We used data from measurements of magnetic fields in the sunspot umbra in the period 1918–2019 at the Mount Wilson Observatory, as well as the tilt angles of ...
Andrey G. Tlatov
doaj   +1 more source

Relationships between relative sunspot numbers and air temperature

Meteorologische Zeitschrift, 1993
Monthly means of relative sunspot numbers (1749-1991) and temperature anomalies of the two hemispheres (1851-1987 for the northern and 1858-1987 for the southern hemisphere) have been analysed by means of spectral methods.
W. Mende, R. Stellmacher, M. Olberg
doaj   +1 more source

Ionospheric electron content at temperate latitudes during the declining phase of the sunspot cycle [PDF]

Ionospheric electron density during declining phase of sunspot cycle by Faraday effect ...
Flaherty, B. J., Yeh, K. C.
core   +1 more source