Results 51 to 60 of about 2,960 (140)

Forecasting Coronal Mass Ejections Using Transformers: A Comparative Study of Flare‐Associated Versus Flare‐Independent Approaches

Space Weather, Volume 23, Issue 8, August 2025.
Abstract Forecasting coronal mass ejections (CMEs) remains a challenge, and no reliable, accurate forecasting method has yet been developed. Knowing that CMEs can occur in association with flares, we compare two approaches: (a) forecasting CMEs by coupling to flare forecasting, and (b) forecasting CMEs independently of flare occurrence.
Julio Hernandez Camero, Lucie M. Green
wiley   +1 more source

Sun-as-a-star variability of Hα and Ca II 854.2 nm lines

Frontiers in Astronomy and Space Sciences
Studies of stellar magnetic fields mostly rely on proxies derived from chromospheric lines, typically forming in the UV and shorter wavelengths and therefore accessible only from space based observatories.
Garrett Zills, Serena Criscuoli, Luca Bertello, Alexei Pevtsov   +3 more
doaj   +1 more source

The Origin of Helicity in Solar Active Regions

, 2004
We present calculations of helicity based on our solar dynamo model and show that the results are consistent with observational data.Comment: To appear in the Proceedings of IAU Symposium ...
Chatterjee, Piyali, Choudhuri, Arnab Rai, Nandy, Dibyendu   +2 more
core   +1 more source

First limits on the 3-200 keV X-ray spectrum of the quiet Sun using RHESSI [PDF]

, 2007
We present the first results using the Reuven Ramaty High-Energy Solar Spectroscopic Imager, RHESSI, to observe solar X-ray emission not associated with active regions, sunspots or flares (the quiet Sun).
Dolan J. F., G. J. Hurford, H. S. Hudson, I. G. Hannah, K. van Bibber, Peterson L. E., R. P. Lin, Strong K. T.   +7 more
core   +1 more source

First Observations of a Geomagnetic Superstorm With a Sub‐L1 Monitor

Space Weather, Volume 23, Issue 3, March 2025.
Abstract Forecasting the geomagnetic effects of solar coronal mass ejections (CMEs) is currently an unsolved problem. CMEs, responsible for the largest values of the north‐south component of the interplanetary magnetic field, are the key driver of intense and extreme geomagnetic activity.
E. Weiler, C. Möstl, E. E. Davies, A. M. Veronig, U. V. Amerstorfer, T. Amerstorfer, J. Le Louëdec, M. Bauer, N. Lugaz, V. Haberle, H. T. Rüdisser, S. Majumdar, M. Reiss   +12 more
wiley   +1 more source

Preliminary Results on Irradiance Measurements from Lyra and Swap

Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012
The first and preliminary results of the photometry of Large Yield Radiometer (LYRA) and Sun Watcher using Active Pixel system detector and Image Processing (SWAP) onboard PROBA2 are presented in this paper. To study the day‐to‐day variations of LYRA irradiance, we have compared the LYRA irradiance values (observed Sun as a star) measured in Aluminum ...
S. T. Kumara, R. Kariyappa, M. Dominique, D. Berghmans, L. Damé, J. F. Hochedez, V. H. Doddamani, Lakshmi Pradeep Chitta, J. Javaraiah   +8 more
wiley   +1 more source

Preface to the special issue on “Old records for new knowledge”

Geoscience Data Journal, Volume 11, Issue 4, Page 357-364, October 2024.
Studying a changing world requires observations going back in time to extend and contextualize our latest scientific knowledge. Old legacy data exist in non‐digital formats. Thus, techniques and methodologies for the preservation, dissemination, interpretation, homogenization, calibration, and use of such legacy data and their associated metadata, as ...
Josep Batlló, Hisashi Hayakawa, Victoria Slonosky, Richard I. Crouthamel   +3 more
wiley   +1 more source

Magnetic Helicity Evolution During the Solar Activity Cycle: Observations and Dynamo Theory

, 2003
We study a simple model for the solar dynamo in the framework of the Parker migratory dynamo, with a nonlinear dynamo saturation mechanism based on magnetic helicity conservation arguments.
Abramenko, Abramenko, Baliunas, Bao, Berger, Blackman, Blackman, Brandenburg, Brandenburg, Brandenburg, Brooke, Bruevich, Chae, Covas, D. Moss, D. Sokoloff, Dikpati, Field, Frisch, Galitski, H. Zhang, Hoyt, I. Rogachevskii, Iroshnikov, K. Kuzanyan, Kleeorin, Kleeorin, Kleeorin, Kleeorin, Kleeorin, Kleeorin, Kleeorin, Kuzanyan, Longcope, N. Kleeorin, Parker, Pevtsov, Pevtsov, Pevtsov, Rogachevskii, Rogachevskii, Rust, Rüdiger, Seehafer, Sofia, Sokoloff, Spruit, Subramanian, Tavakol, Wang, Woltjer, Zhang, Zhang, Zhang, Zhang, Zhang   +55 more
core   +1 more source

Design of the microelectromechanical logic element based on a comb-drive resonator

Научно-технический вестник информационных технологий, механики и оптики
CMOS technology has nearly reached the physical limits of transistor scaling and exhibits significant operational limitations at extreme temperatures and ionizing radiation.
A. A. Solovev, E. F. Pevtsov, V. A. Kolchuzhin   +2 more
doaj   +1 more source

A Statistical Study on Photospheric Magnetic Nonpotentiality of Active Regions and Its Relationship with Flares during Solar Cycles 22-23

, 2012
A statistical study is carried out on the photospheric magnetic nonpotentiality in solar active regions and its relationship with associated flares. We select 2173 photospheric vector magnetograms from 1106 active regions observed by the Solar Magnetic ...
A. Antalova, A. Nindos, A.A. Pevtsov, A.A. Pevtsov, A.B. Severny, C.J. Schrijver, D.A. Falconer, D.A. Falconer, D.M. Rust, G.A. Gary, G.A. Gary, G.E. Moreton, G.X. Ai, G.X. Ai, GangHua Lin, H. Li, H.M. Wang, H.Q. Xu, H.Q. Zhang, H.Q. Zhang, HongQi Zhang, J. Guo, J. Guo, J. Guo, J. Guo, J. Hao, J. Jing, J.P. Dun, J.T. Su, J.X. Wang, Juan Guo, K.D. Leka, M. Hagino, M.J. Hagyard, M.J. Hagyard, N. Seehafer, N.C. Joshi, O.V. Chumak, O.V. Chumak, S.-H. Park, S.D. Bao, S.D. Bao, S.D. Bao, S.K. Tiwari, T. Sakurai, T.J. Wang, T.J. Wang, U. Feldman, V.I. Abramenko, Xiao Yang, Y. Nakagawa, Y.-J. Moon, Y.M. Cui, Y.M. Cui, Y.M. Cui, Y.P. Lü, Y.Y. Deng, Yu Gao   +57 more
core   +1 more source