SUMER - Solar Ultraviolet Measurements of Emitted Radiation

Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.; Grewing, M.; Huber, M. C. E.; Jordan, M.; Lemaire, Philippe; Marsch, E.; Poland, A. I.

doi:10.1007/bf00733430

Cited by 692 publications

(435 citation statements)

References 13 publications

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“…Spectrographs such as SUMER [52], EIS [53] or IRIS [54] provide not only Doppler shifts to deduce the velocities but also ratios of emission lines that can be used to deduce temperature, density or even elemental abundances, as noted in textbooks, e.g. [55].…”

Section: (A) Inversions Of Observationsmentioning

confidence: 99%

What can large-scale magnetohydrodynamic numerical experiments tell us about coronal heating?

Peter

2015

Phil. Trans. R. Soc. A.

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The upper atmosphere of the Sun is governed by the complex structure of the magnetic field. This controls the heating of the coronal plasma to over a million kelvin. Numerical experiments in the form of threedimensional magnetohydrodynamic simulations are used to investigate the intimate interaction between magnetic field and plasma. These models allow one to synthesize the coronal emission just as it would be observed by real solar instrumentation. Largescale models encompassing a whole active region form evolving coronal loops with properties similar to those seen in extreme ultraviolet light from the Sun, and reproduce a number of average observed quantities. This suggests that the spatial and temporal distributions of the heating as well as the energy distribution of individual heat deposition events in the model are a good representation of the real Sun. This provides evidence that the braiding of fieldlines through magneto-convective motions in the photosphere is a good concept to heat the upper atmosphere of the Sun.

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Section: (A) Inversions Of Observationsmentioning

confidence: 99%

What can large-scale magnetohydrodynamic numerical experiments tell us about coronal heating?

Peter

2015

Phil. Trans. R. Soc. A.

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“…emitted intensity) observations at solar-disk center. The comparisons use some quiet-Sun atlases derived from the following instruments: Solar Ultraviolet Measurements of Emitted Radiation (SUMER: Wilhelm et al, 1995) onboard SOHO, EUV Imaging Spectrometer (EIS: Culhane et al, 2007) onboard Hinode, and the Coronal Diagnostic Spectrometer (CDS: Harrison et al, 1995) onboard SOHO. In all cases, we convolved the computed spectrum with the instrument resolution, which is known for the first two instruments but lesser understood for CDS.…”

Section: Comparison Of Emitted Intensity (Radiance) With Observationsmentioning

confidence: 99%

Far- and Extreme-UV Solar Spectral Irradiance and Radiance from Simplified Atmospheric Physical Models

et al. 2013

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This article describes an update of the physical models that we use to reconstruct the FUV and EUV irradiance spectra and the radiance spectra of the features that at any given point in time may cover the solar disk depending on the state of solar activity. The present update introduces important modifications to the chromosphere-corona transition region of all models. Also, the update introduces improved and extended atomic data. By these changes, the agreement of the computed and observed spectra is largely improved in many EUV lines important for the modeling of the Earth's upper atmosphere. This article describes the improvements and shows detailed comparisons with EUV/FUV radiance and irradiance measurements. The solar spectral irradiance from these models at wavelengths longer than ≈ 200 nm is discussed in a separate article.

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“…For the evaluation of the variabilities in both intensity and Doppler shift as well as differential emission measures quiet regions at Sun centre have been observed using the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer (Wilhelm et al 1995) 25 February 1997 (D. Gigas) using the 1 × 300 slit #2 and on 22, 23 and 25 April 1997 (I. Rüedi) using 120 long slits #3 (1 wide) and #6 (0.3 wide). The pixel size was 1 × 1 , except for the slit #6 where it was 0.3 × 1 .…”

Section: Observationsmentioning

confidence: 99%

Variability of EUV-spectra from the quiet upper solar atmosphere: Intensity and Doppler shift

Brković

Peter

Solanki

2003

A&A

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Abstract.We have studied SUMER and CDS time series of spectra and images of quiet-Sun regions at the solar disc centre. The data contain ultraviolet emission lines sampling temperatures of the chromosphere, transition region and corona. We find a high correlation between average net Doppler shifts and relative brightness variabilities of the studied lines (correlation coefficient of 0.92), suggesting a connection between the two quantities. The anti-correlation between differential emission measures and relative brightness variabilities is weaker (correlation coefficient of −0.78). We discuss the observed relationships on the basis of differential emission measures and linear wave calculations.

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SUMER - Solar Ultraviolet Measurements of Emitted Radiation

Cited by 692 publications

References 13 publications

What can large-scale magnetohydrodynamic numerical experiments tell us about coronal heating?

What can large-scale magnetohydrodynamic numerical experiments tell us about coronal heating?

Far- and Extreme-UV Solar Spectral Irradiance and Radiance from Simplified Atmospheric Physical Models

Variability of EUV-spectra from the quiet upper solar atmosphere: Intensity and Doppler shift

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