COMMISSION 10: SOLAR ACTIVITY

Commission 10 deals with solar activity in all of its forms, ranging from the smallest nanoflares to the largest coronal mass ejections. This report reviews scientific progress over the roughly two-year period ending in the middle of 2008. This has been an exciting time in solar physics, highlighted by the launches of the Hinode and STEREO missions late in 2006. The report is reasonably comprehensive, though it is far from exhaustive. Limited space prevents the inclusion of many significant results. The report is divided into the following sections: Photosphere and chromosphere; Transition region; Corona and coronal heating; Coronal jets; flares; Coronal mass ejection initiation; Global coronal waves and shocks; Coronal dimming; The link between low coronal CME signatures and magnetic clouds; Coronal mass ejections in the heliosphere; and Coronal mass ejections and space weather. Primary authorship is indicated at the beginning of each section.

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Single and Multiwavelength Detection of Coronal Dimming and Coronal Wave Using Faster R-CNN

Advances in Astronomy ◽

10.1155/2019/7821025 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Zongxia Xie ◽

Chunyang Ji

Keyword(s):

Deep Learning ◽

Space Weather ◽

Coronal Mass Ejections ◽

Solar Physics ◽

Automatic Detection ◽

Solar Dynamics Observatory ◽

Solar Events ◽

Solar Dynamics ◽

Coronal Dimming ◽

Coronal Wave

Automatic detection of solar events, especially uncommon events such as coronal dimming (CD) and coronal wave (CW), is very important in solar physics research. The CD and CW are not only related to the detection of coronal mass ejections (CMEs) but also affect space weather. In this paper, we have studied methods for automatically detecting them. In addition, we have collected and processed a dataset that includes the solar images and event records, where the solar images come from the Atmospheric Imaging Assembly (AIA) of Solar Dynamics Observatory (SDO) and the event records come from Heliophysics Event Knowledgebase (HEK). Different from the methods used before, we introduce the idea of deep learning. We train single-wavelength and multiwavelength models based on Faster R-CNN. In terms of accuracy, the single-wavelength model performs better. The multiwavelength model has a better detection performance on multiple solar events than the single-wavelength model.

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Coronal mass ejection: key issues

Proceedings of the International Astronomical Union ◽

10.1017/s1743921309029305 ◽

2008 ◽

Vol 4 (S257) ◽

pp. 191-200

Author(s):

Richard Harrison

Keyword(s):

Coronal Mass Ejection ◽

Coronal Mass Ejections ◽

Research Community ◽

Significant Progress ◽

International Effort ◽

Recent Advances ◽

Key Issues ◽

Active Research ◽

Mass Ejection ◽

Coronal Dimming

AbstractCoronal Mass Ejections (CMEs) have been addressed by a particularly active research community in recent years. With the advent of the International Heliophysical Year and the new STEREO and Hinode missions, in addition to the on-going SOHO mission, CME research has taken centre stage in a renewed international effort. This review aims to touch on some key observational areas, and their interpretation. First, we consider coronal dimming, which has become synonymous with CME onsets, and stress that recent advances have heralded a move from a perceived association between the two phenomena to a firm, well-defined physical link. What this means for our understanding of CME modeling is discussed. Second, with the new STEREO observations, and noting the on-going SMEI observations, it is important to review the opening field of CME studies in the heliosphere. Finally, we discuss some specific points with regard to EIT-waves and the flare-CME relationship. In the opinion of the author, these issues cover key hot topics which need consideration for significant progress in the field.

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Coronal mass ejection

Philosophical Transactions of the Royal Society of London Series A Physical and Engineering Sciences ◽

10.1098/rsta.1991.0090 ◽

1991 ◽

Vol 336 (1643) ◽

pp. 401-412 ◽

Cited By ~ 28

Keyword(s):

Solar Activity ◽

Coronal Mass Ejection ◽

Coronal Mass Ejections ◽

Set Up ◽

Mass Ejection ◽

Solar Coronal

We summarize the observational aspects of the transient solar coronal features known as coronal mass ejections. Recognizing the importance of understanding this form of solar activity, particularly in the light of relations to flare and prominence activity, and geomagnetic effects, we consider the spectrum of models which have been used to describe these events and assess their viability. We find most models to be unphysical and all represent a gross over simplification of solar conditions. In conclusion we set up a cartoon model which best fits the observations and which we feel should be further developed.

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The Coronal‐dimming Footprint of a Streamer‐Puff Coronal Mass Ejection: Confirmation of the Magnetic‐Arch‐Blowout Scenario

The Astrophysical Journal ◽

10.1086/516620 ◽

2007 ◽

Vol 661 (1) ◽

pp. 543-550 ◽

Cited By ~ 35

Author(s):

Ronald L. Moore ◽

Alphonse C. Sterling

Keyword(s):

Coronal Mass Ejection ◽

Mass Ejection ◽

Magnetic Arch ◽

Coronal Dimming

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On the Association between Coronal Mass Ejections and Coronal Holes

International Astronomical Union Colloquium ◽

10.1017/s0252921100154259 ◽

1989 ◽

Vol 104 (2) ◽

pp. 239-242

Author(s):

V.K. Verma ◽

M.C. Pande

Keyword(s):

Magnetic Field ◽

Coronal Mass Ejection ◽

Coronal Mass Ejections ◽

Solar Flares ◽

Coronal Holes ◽

Mass Ejection ◽

Open Magnetic Field

AbstractThe coronal mass ejection (CME) data and the data for coronal holes for the period 1979-1982 are compared locationwise. Out of 79 CMEs whose locations and spans are known, 48 (61%) CMEs are associated with coronal holes. We make a tentative suggestion that probably the mass ejected during solar flares and active prominences may move along the open magnetic field of the coronal holes and appear as CMEs.

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The association of coronal mass ejection transients with other forms of solar activity

Solar Physics ◽

10.1007/bf00155456 ◽

1979 ◽

Vol 61 (1) ◽

pp. 201-215 ◽

Cited By ~ 366

Author(s):

R. H. Munro ◽

J. T. Gosling ◽

E. Hildner ◽

R. M. MacQueen ◽

A. I. Poland ◽

...

Keyword(s):

Solar Activity ◽

Coronal Mass Ejection ◽

Mass Ejection

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SOLAR SPECTROPOLARIMETER FOR SPACE WEATHER FORECAST

Solar-Terrestrial Physics ◽

10.12737/stp-54201903 ◽

2019 ◽

Vol 5 (4) ◽

pp. 21-26

Author(s):

Evgeniy Ivanov ◽

Aleksey Gubin ◽

Sergey Lesovoi ◽

Ramses Zaldivar Estrada

Keyword(s):

Solar Activity ◽

Space Weather ◽

Linear Polarization ◽

Coronal Mass Ejections ◽

Software Defined Radio ◽

Low Cost ◽

Weather Forecast ◽

The Internet ◽

Type Ii ◽

Continuous Observation

We propose a project of the meter wavelength range solar spectropolarimeter designed for a ground-based network developing for space weather forecast. The Software-Defined Radio (SDR) solution is chosen to meet such instrument network requirements as specification identity, low cost, possibility of controlling and transmitting data remotely via the Internet. Along with these requirements, the proposed SDR solution allows us to measure Stokes I and V easily, which contrasts the proposed instrument with e-CALLISTO network spectropolarimeters, most of which can record only one linear polarization. Deployment of such instruments at various longitudes will allow continuous observation of type II bursts, often related to coronal mass ejections (CMEs) — the most geoeffective solar activity events that affect the space weather significantly.

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Optical instrumentation for chromospheric monitoring during solar cycle 25 at Paris and Côte d’Azur observatories

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2020032 ◽

2020 ◽

Vol 10 ◽

pp. 31

Author(s):

Jean-Marie Malherbe ◽

Thierry Corbard ◽

Kevin Dalmasse

Keyword(s):

Solar Activity ◽

Solar Cycle ◽

Space Weather ◽

Coronal Mass Ejections ◽

Calibration Method ◽

Line Profiles ◽

Short Term ◽

Optical Instruments ◽

Dynamic Events

We present the observing program proposed by Paris and Côte d’Azur Observatories for monitoring solar activity during the upcoming cycle 25 and providing near real time images and movies of the chromosphere for space-weather research and applications. Two optical instruments are fully dedicated to this task and we summarize their capabilities. Short-term and fast-cadence observations of the chromosphere will be performed automatically at Calern observatory (Côte d’Azur), where dynamic events, as flare development, Moreton waves, filament instabilities and Coronal Mass Ejections onset, will be tracked. This new set of telescopes will operate in 2021 with narrow bandpass filters selecting Hα and CaII K lines. We present the instrumental design and a simulation of future images. At Meudon, the Spectroheliograph is well adapted to the long-term and low-cadence survey of chromospheric activity by recently improved and optimized spectroscopic means. Surface scans deliver daily (x, y, λ) datacubes of Hα, CaII K and CaII H line profiles. We describe the nature of available data and emphasize the new calibration method of spectra.

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