The structure of the solar corona, the outermost regions of the Sun's atmosphere, can be monitored using radio waves (100’s of MHz to 10’s of GHz). Variations in the radio wave spectrum reveal characteristics of the corona and upper chromosphere in terms of altitude profile for the local plasma temperature, density and magnetic field. Typically, the lower the frequency, the higher the height of origin.
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 Print Publications.
Questions and comments may be directed to ncei.info@noaa.gov
About
Radio bursts are associated with solar flares. The signal arrival time delay at Earth of the different radio frequencies during burst events is due to the outward movement of the source. Large bursts last 10 to 20 minutes on average. Longer radio noise storms of persistent and variable high levels of radiation originate in sunspot groups, areas of large, intense magnetic fields.
Data Access
Culgoora Observatory Monthly Tables (2011-2014)
Culgoora Observatory Monthly Tables (2011-2014)
Fixed Frequency Observations
Multiple observatories, bursts detected at specific frequencies annual tables (1960-2010)
Spectrally Resolved Burst Tables
Multiple observatories, annual tables (1967-2010) Simple and detailed versions
Daily Full Solar Disk Radio Flux Measurements (1947–2015)
Measurements taken at local noon at various solar radio observatories. Observatories include facilities in the Solar Electro-Optical Network (SEON, RSTN, SOON), Krakow, and Penticton. Date coverage and observed frequencies vary.
National Research Council Canada, specifically the Penticton observatory, is the current worldwide provider of F10.7 data.
Daily Maps of Solar Radio Emissions
- Nobeyama Solar Radio Observatory(2002-2011)
- Wilcox Solar Observatory (Stanford) (1962-1973)
- These maps are in text format.
- See the documentation for how to interpret the text table into maps.
Data Access
Daily mean radio flux densities for 55 different observatories (1949–1986) per the quarterly IAU Bulletin.