Electron temperature maps of the low solar corona: ISCORE results from the total solar eclipse of 1 August 2008 in China

Reginald, N. L.; Davila, J. M.; Cyr, O. C. St.; Rabin, D. M.

doi:10.1002/2017ja024014

Cited by 6 publications

(2 citation statements)

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“…CMO can be launched by several existing vehicles (including Falcon 9) and is compatible with the ESPA ring payload adapter. The coronagraph will measure electron temperature and radial flow speed in the K-corona using the filter-ratio method explicated by Cram [25] and Reginald and Davila [26] and demonstrated by ground-based and balloonborne instruments [27] [28]. The coronagraph will also obtain narrowband images of the emission-line corona, including at least Fe XI 789.2 nm and Fe XIV 530.3 nm (Figure 4.2), following the diagnostic rationale presented by Habbal et al [29].…”

Section: Coronal Microscale Observatory (Cmo)mentioning

confidence: 99%

Observing Coronal Microscales and their Connection with Mesoscales

Rabin,

Novo-Gradac,

Daw

et al. 2023

Bulletin of the AAS

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It has been known since the dawn of modern eclipse observations that the solar corona is structured on all scales from the solar radius to the limit of ground-based imaging (until the advent of adaptive optics, about 1 arcsec). Early space-based imaging at soft x-ray and extreme ultraviolet (EUV) wavelengths confirmed pervasive structure in the hot coronal plasma and added diagnostic power. During the same period, magnetograms revealed structure in the photospheric magnetic field at all observable scales and spawned the study of magnetic flux tubes. Because magnetic pressure dominates gas pressure in the corona (low β), it was clear that the magnetic field guides coronal structure. However, that alone does not dictate the density and temperature structure of the corona or determine on what spatial scales inhomogeneity will occur. It was equally clear that the physical mechanism(s) responsible for heating the corona ultimately determine those scales, and, consequently, that observing them would be key to understanding coronal heating. This leads immediately to the question: What spatial and temporal scales are present, and what scales are theoretically anticipated? In a seminal paper, Parker introduced the idea of topological dissipation: that magnetic flux tubes rooted in the photosphere, jostled by turbulent convection, will progressively develop fine structure down to scales that ultimately result in magnetic reconnection [1]. Parker further developed his theory and coined the term "nanoflare" for such small-scale heating events [2]. Notwithstanding the still-debated applicability of topological dissipation in the corona [3], it seems highly likely that random motions of magnetic footpoints in the photosphere will inevitably lead to very fine-scale structure in the coronal magnetic field. Thus, whether reconnection, wave dissipation, or both are responsible for local heating, the heated volumes are expected to possess structure on similarly fine scales.

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Section: Coronal Microscale Observatory (Cmo)mentioning

confidence: 99%

Observing Coronal Microscales and their Connection with Mesoscales

Rabin,

Novo-Gradac,

Daw

et al. 2023

Bulletin of the AAS

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“…The pixel size of the polarization data is about 12.7 arcsec, and we used 3 by 3 data binning of stacked images after aligning the images for specific filters and polarization angles to obtain a temperature map. The temperature measurements using the pass-band ratio imaging has been conducted during the TSE (Reginald et al 2017) and Balloon mission (Gopalswamy et al 2020). More detailed description of the DICE instrument and data reduction can be found in .…”

Section: Observations and Data Processingmentioning

confidence: 99%

On the Nature of Propagating Intensity Disturbances in Polar Plumes during the 2017 Total Solar Eclipse

Cho,

Madjarska

et al. 2021

Preprint

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The propagating intensity disturbances (PIDs) in plumes are still poorly understood and their identity (magnetoacoustic waves or flows) remains an open question. We investigate PIDs in five plumes located in the northern polar coronal hole observed during the 2017 total solar eclipse. Three plumes are associated with coronal bright points, jets and macrospicules at their base (active plumes) and the other two plumes are not (quiet plumes). The electron temperature at the base of the plumes is obtained from the filter ratio of images taken with the X-ray Telescope on board Hinode and the passband ratio around 400 nm from an eclipse instrument, the Diagnostic Coronagraph Experiment (DICE). The phase speed (v r ), frequency (ω), and wavenumber (k) of the PIDs in the plumes are obtained by applying a Fourier transformation to the spacetime (r − t plane) plots in images taken with the Atmospheric Imaging Assembly (AIA) in three different wavelength channels (171 Å, 193 Å, and 211 Å). We found that the PIDs in the higher temperature AIA channels, 193 and 211 Å, are faster than that of the cooler AIA 171 Å channel. This tendency is more significant for the active plumes than the quiet ones. The observed speed ratio (∼1.3) between the AIA 171 and 193 Å channels is similar to the theoretical value (1.25) of a slow magnetoacoustic wave. Our results support the idea that PIDs in plumes represent a superposition of slow magnetoacoustic waves and plasma outflows that consist of dense cool flows and hot coronal jets.

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