The solar corona is the outermost layer of the Sun’s atmosphere. It is characterized by very hot, diffuse plasma (1 - 10 million degrees Kelvin). The corona can be observed through a variety of methods. Ground-based coronagraphs observe the corona in the optical or infrared parts of the electromagnetic spectrum. From space, emission lines in the extreme ultraviolet and soft X-ray regimes are observed.
NOAA/NCEI has acquired these legacy data sets from multiple sources over many decades. The data presented here are provided, ‘as is,’ and in most cases the linked documentation is the entirety of available information. In some cases, older data may also be found in the Space Weather Legacy Publications.
Questions and comments may be directed to ncei.info@noaa.gov.
GOES-15 SXI X-ray image of the sun 6/26/2014
Coronagraphs Details
Coronagraphs are a unique optical instrument designed to mask out the bright solar disk to allow scientists to observe the extended and tenuous corona. Coronagraphs are used to track coronal mass ejections which can produce space weather that affects Earth.
Lomnicky
- Contour Plots
- 5-degree data
- Yearly text tables measurements are taken every five degrees around the solar disk (counterclockwise). Values are in millionths of intensity of the solar disk (coronal units) and converted to the photometrical scale of Lomnicky Stit Station at a height of 40 minutes above the solar limb.
Sac Peak
- Daily contour plots: These data were created based on observations by the National Solar Observatory.
SXI
See the “Solar Imagery” tab on the GOES 1–15 page for more information on and data from the Soft X-Ray Instrument (SXI). The first SXI instrument was hosted on GOES-12.
Solar Coronal Index Details
The coronal index of solar activity (CI) characterizes the coronal activity of the ‘‘Sun as a star’’ and represents the total irradiance of the coronal green line (Fe XIV 530.3 nm) emitted by the Sun's visible hemisphere. CI is calculated using the homogenized Fe XIV 530.3 nm coronal emission line ground-based measurements from the worldwide net of the coronal stations (Rybansky', 1975; Rybansky' et al.,1994, 2001; Xanthakis et al., 1990).
Lomnicky
Slovak
Documentation for the Lomnicky and Slovak datasets is available Solar Corona Documentation.
Catalogs of coronal hole parameters are listed below. The data come primarily from the Vacuum Solar Telescope at Kitt Peak National Observatory using the He I 10830A line.
Kitt Peak, 1083nm
Solar Corona/Coronal Holes 1970–1995
- Catalog of Coronal Holes 1970-1991 -- Report UAG-102 descriptive text
- Format
- Table 1 -- Catalog of polar holes 1970-July 1995
- Table 2 -- Catalog of equatorial holes 1970-July 1995
- Table 3 -- Catalog of long duration polar holes 1970-July 1995
- Table 4 -- Catalog of long duration equatorial holes 1970-July 1995
- Table 5 -- Catalog of all holes August-September 1995