The systematic radial downflow in the transition region of the quiet sun from limb-to-limb observations of the C IV resonance lines

1990 ◽  
Vol 358 ◽  
pp. 693 ◽  
Author(s):  
Gary J. Rottman ◽  
Donald D. Hassler ◽  
Michael D. Jones ◽  
Frank Q. Orrall
Keyword(s):  
Transition Region ◽  
Quiet Sun

SUMER Observations of the Quiet‐Sun Transition Region

1999 ◽  
Vol 512 (2) ◽  
pp. 992-1005 ◽  
Author(s):  
N. W. Griffiths ◽  
G. H. Fisher ◽  
D. T. Woods ◽  
O. H. W. Siegmund
Keyword(s):  
Transition Region ◽  
Quiet Sun

scholarly journals Observations of the Quiet Sun with 6″ Resolution

1980 ◽  
Vol 86 ◽  
pp. 53-55
Author(s):  
M. R. Kundu ◽  
A. P. Rao ◽  
F. T. Erskine ◽  
J. D. Bregman
Keyword(s):  
High Resolution ◽  
Radio Emission ◽  
Transition Region ◽  
Spatial Resolution ◽  
Radio Telescope ◽  
Solar Radio ◽  
High Spatial Resolution ◽  
Solar Radio Emission ◽  
Quiet Sun ◽  
Millimeter Wavelengths

Solar radio emission at centimeter and millimeter wavelengths originates in the chromosphere and transition region and is a useful probe for the temperature and density in these regions. High spatial resolution observations of the quiet sun provide valuable information on the structure of the solar atmosphere. We have performed high resolution (~ 6″ (E-W) x 15″ (N-S)) observations at 6 cm with the Westerbork Synthesis Radio Telescope (WSRT) in June 1976 in order to search for the radio analog of the supergranulation network and to study the extent and symmetry of limb brightening. The use of the WSRT for high spatial resolution solar mapping has been described by Bregman and Felli (1976), Kundu et al. (1977), and others.

scholarly journals Structure of sunspot light bridges in the chromosphere and transition region

2018 ◽  
Vol 609 ◽  
pp. A73 ◽  
Author(s):  
R. Rezaei
Keyword(s):  
Transition Region ◽  
Line Width ◽  
Solar Limb ◽  
Solar Radius ◽  
Spectral Lines ◽  
Quiet Sun ◽  
Hot Plasma ◽  
Emission Enhancement ◽  
Energy And Momentum ◽  
Far Ultraviolet

Context. Light bridges (LBs) are elongated structures with enhanced intensity embedded in sunspot umbra and pores. Aims. We studied the properties of a sample of 60 LBs observed with the Interface Region Imaging Spectrograph (IRIS). Methods. Using IRIS near- and far-ultraviolet spectra, we measured the line intensity, width, and Doppler shift; followed traces of LBs in the chromosphere and transition region (TR); and compared LB parameters with umbra and quiet Sun. Results. There is a systematic emission enhancement in LBs compared to nearby umbra from the photosphere up to the TR. Light bridges are systematically displaced toward the solar limb at higher layers: the amount of the displacement at one solar radius compares well with the typical height of the chromosphere and TR. The intensity of the LB sample compared to the umbra sample peaks at the middle/upper chromosphere where they are almost permanently bright. Spectral lines emerging from the LBs are broader than the nearby umbra. The systematic redshift of the Si iv line in the LB sample is reduced compared to the quiet Sun sample. We found a significant correlation between the line width of ions arising at temperatures from 3 × 104 to 1.5 × 105 K as there is also a strong spatial correlation among the line and continuum intensities. In addition, the intensity−line width relation holds for all spectral lines in this study. The correlations indicate that the cool and hot plasma in LBs are coupled. Conclusions. Light bridges comprise multi-temperature and multi-disciplinary structures extending up to the TR. Diverse heating sources supply the energy and momentum to different layers, resulting in distinct dynamics in the photosphere, chromosphere, and TR.

scholarly journals WHAT IS THE SOURCE OF QUIET SUN TRANSITION REGION EMISSION?

2016 ◽  
Vol 831 (2) ◽  
pp. 158 ◽  
Author(s):  
D. J. Schmit ◽  
Bart De Pontieu
Keyword(s):  
Transition Region ◽  
Quiet Sun

scholarly journals HIGH-SPEED TRANSITION REGION AND CORONAL UPFLOWS IN THE QUIET SUN

2009 ◽  
Vol 707 (1) ◽  
pp. 524-538 ◽  
Author(s):  
Scott W. McIntosh ◽  
Bart De Pontieu
Keyword(s):  
Transition Region ◽  
High Speed ◽  
Quiet Sun

TRACE Emission Heights Estimated from TRACE Limb Observations

2001 ◽  
Vol 203 ◽  
pp. 431-433
Author(s):  
M. Zhang
Keyword(s):  
Transition Region ◽  
Coronal Holes ◽  
Active Regions ◽  
Height Variation ◽  
Quiet Sun ◽  
Trace Data ◽  
Coronal Structures

While TRACE data have provided us much information of transition region and coronal structures, many TRACE data users would like to have a knowledge of emission heights of TRACE bands. By analyzing TRACE limb observations, we give an average estimation of emission heights of TRACE 171, 195 and 1216 bands for different features like quiet Sun regions, active regions and coronal holes. Average emission heights over the limb are also discussed. Previous equator-to-pole height variation is further confirmed by TRACE data when averaging on quiet Sun regions. If averaging for all fluxes, a reverse equator-to-pole height variation is shown.

scholarly journals SUMER Observations of the Solar Transition Region: Spatial and Temporal Behaviour

2001 ◽  
Vol 203 ◽  
pp. 425-427
Author(s):  
L. Teriaca ◽  
J. G. Doyle ◽  
D. Banerjee
Keyword(s):  
High Resolution ◽  
Wavelet Analysis ◽  
Transition Region ◽  
Line Width ◽  
Doppler Shift ◽  
Temporal Behaviour ◽  
Quiet Sun ◽  
Solar Transition Region ◽  
Solar Transition ◽  
Width Measurements

We examine the spatial and temporal behaviour of the quiet Sun transition region (TR) using high resolution SUMER observations in O VI 1032 Å. A detailed study of raster images allows us to differentiate the network and internetwork through Doppler shift and line width measurements. The oscillatory nature of the TR is investigated using wavelet analysis over a series of spectra obtained with high temporal cadence.

Transition region quiet sun velocity field evolution

2002 ◽  
Vol 30 (3) ◽  
pp. 487-490 ◽  
Author(s):  
P. Lemaire ◽  
G. Artzner ◽  
J.-C. Vial ◽  
W. Curdt ◽  
U. Schühle ◽  
...  
Keyword(s):  
Velocity Field ◽  
Transition Region ◽  
Quiet Sun ◽  
Field Evolution
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