Evolution of active region outflows throughout an active region lifetime

Zangrilli, L.; Poletto, G.

doi:10.1051/0004-6361/201628421

Cited by 17 publications

(16 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Upflowing plasma is observed by Hinode/EIS in approximately the same locations for at least 8-9 days as ARs transit the solar disk (Démoulin et al, 2013). Recently, Zangrilli and Poletto (2016) have shown that the upflows persist for much longer periods. Using data from Solar and Heliospheric Observatory's Ultraviolet Coronagraph Spectrometer (SOHO/UVCS), they demonstrated that upflows from AR 8100 extended into the intermediate corona to become outflows and persisted for the AR's entire lifetime which spanned five solar rotations.…”

Section: General Characteristics Of Active Region Upflowsmentioning

confidence: 87%

Apparent and Intrinsic Evolution of Active Region Upflows

et al. 2017

View full text Add to dashboard Cite

We analyze the evolution of Fe XII coronal plasma upflows from the edges of ten active regions (ARs) as they cross the solar disk using the Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) to do this. Confirming the results of Démoulin et al. (Sol. Phys. 283, 341, 2013), we find that for each AR there is an observed long-term evolution of the upflows. This evolution is largely due to the solar rotation that progressively changes the viewpoint of dominantly stationary upflows. From this projection effect, we estimate the unprojected upflow velocity and its inclination to the local vertical. AR upflows typically fan away from the AR core by 40°to nearly vertical for the following polarity. The span of inclination angles is more spread out for the leading polarity, with flows angled from −29°(inclined toward the AR center) to 28°(directed away from the AR). In addition to the limb-to-limb apparent evolution, we identify an intrinsic evolution of the upflows that is due to coronal activity, which is AR dependent. Furthermore, line widths are correlated with Electronic supplementary material The online version of this article

show abstract

Section: General Characteristics Of Active Region Upflowsmentioning

confidence: 87%

Apparent and Intrinsic Evolution of Active Region Upflows

et al. 2017

View full text Add to dashboard Cite

show abstract

“…3. Images and spectra of active regions show rapid flows with speeds of at least 100 km s −1 along their fanned-out edges (e.g., Harra et al 2008;Brooks and Warren 2011;Morgan 2013;Zangrilli and Poletto 2016). The slow solar wind associated with these structures may come from small, short-lived coronal holes adjacent to the active regions themselves ).…”

Section: Periodicities Linking the Sun And Heliospherementioning

confidence: 99%

Origins of the Ambient Solar Wind: Implications for Space Weather

2017

View full text Add to dashboard Cite

The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, streamstream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress-in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory-that gives us hope that the above problems are indeed solvable.

show abstract

“…There are also investigations of the long-term (time scales covering a full AR lifetime or more) evolution of, e.g the magnetic influence of AR plasma flows (e.g. Harra et al 2017;Zangrilli andPoletto 2016 andKo et al 2016), the CME production rate along the solar cycle (e.g. Gopalswamy et al 2003 andRiley et al 2006), the global magnetic field and its associated CME production (Petrie, 2013), and the continuous tracking of some AR magnetic properties (e.g.…”

Section: Introductionmentioning

confidence: 99%

Analysis of a long-duration AR throughout five solar rotations: Magnetic properties and ejective events

Iglesias

Cremades

Merenda

et al. 2020

Advances in Space Research

View full text Add to dashboard Cite

Coronal mass ejections (CMEs), which are among the most magnificent solar eruptions, are a major driver of space weather and can thus affect diverse human technologies. Different processes have been proposed to explain the initiation and release of CMEs from solar active regions (ARs), without reaching consensus on which is the predominant scenario, and thus rendering impossible to accurately predict when a CME is going to erupt from a given AR. To investigate AR magnetic properties that favor CMEs production, we employ multi-spacecraft data to analyze a long duration AR (NOAA 11089, 11100, 11106, 11112 and 11121) throughout its complete lifetime, spanning five Carrington rotations from July to November 2010. We use data from the Solar Dynamics Observatory to study the evolution of the AR magnetic properties during the five near-side passages, and a proxy to follow the magnetic flux changes when no magnetograms are available, i.e. during farside transits. The ejectivity is studied by characterizing the angular widths, speeds and masses of 108 CMEs that we associated to the AR, when examining a 124-day period. Such an ejectivity tracking was possible thanks to the mulit-viewpoint images provided by the Solar-Terrestrial Relations Observatory and Solar and Heliospheric Observatory in a quasi-quadrature configuration. We also inspected the X-ray flares registered by the GOES satellite and found 162 to be associated to the AR under study. Given the substantial number of ejections studied, we use a statistical approach instead of a single-event analysis. We found three well defined periods of very high CMEs activity and two periods with no mass ejections that are preceded or accompanied by characteristic changes in the AR magnetic flux, free magnetic energy and/or presence of electric currents. Our large sample of CMEs and long term study of a single AR, provide further evidence relating AR magnetic activity to CME and Flare production.

show abstract

Evolution of active region outflows throughout an active region lifetime

Cited by 17 publications

References 53 publications

Apparent and Intrinsic Evolution of Active Region Upflows

Apparent and Intrinsic Evolution of Active Region Upflows

Origins of the Ambient Solar Wind: Implications for Space Weather

Analysis of a long-duration AR throughout five solar rotations: Magnetic properties and ejective events

Contact Info

Product

Resources

About