Solar RadioEntry ID: gov.noaa.ngdc.stp.solar.solar-features_solar-features_solar-radio
Abstract: Scientists monitor the structure of the solar corona, the outer most regions of the Sun's atmosphere, using radio waves (100?s of MHz to 10?s of GHz). Variations in the
radiowave 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 then ... the higher the height of origin. The frequency, like the solar electron density, decreases uniformly outwards with 245 MHz originating high in the corona whereas 15,400 MHz
originates in the low corona. Radio bursts are associated with solar flares. The delay at Earth of the different radio frequencies during burst events is due to the outward movement of the source.
Bursts can have temperatures of 10xE12 degrees Kelvin. 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. These storms are strongly circularly polarized due to the intense magnetic fields. The microwave wavelength 2800 MHz daily radio flux
correlates highly with the daily sunspot number and the two databases are used interchangeably. The 2800 MHz, or 10.7 cm, responds to the same conditions that produce changes in the visible and
X-ray wavelengths. Schmahl and Kundu (1995) find that the solar radio fluxes in the spectral range 1000-9400 MHz correlate well with the total solar irradiance. The intermediate frequencies
(at 2800 and 3750 MHz) are produced mainly by free-free gyroresonance emission from sunspot structures, while 1000 and 9400 MHz flux are produced mainly by free-free processes from structures
associated with plages. They can distinguish plage-associated emission from spot-associated emission in the time series of microwave flux, both contributing opposing effects on the total
Purpose: To provide scientific data stewardship of solar-terrestrial datasets in compliance with NOAA Administrative Order (NAO) 212-15, "Management of Environmental and Geospatial Data and Information", dated 04 Nov 10. Scientific Data Stewardship includes the Archive, Access, and Assessment (AAA) of operational and related solar and space environmental datasets.
Data Set Citation
Dataset Originator/Creator: Scientific Data Stewardship provided by the National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce.
Dataset Title: Solar Radio
Dataset Release Date: 2012-10-14
Start Date: 1955-07-01Stop Date: 2010-11-24
Use Constraints Access Constraints: None Use Constraints: None Distribution
Liability: While every effort has been made to ensure that these data are
accurate and reliable within the limits of the current state of the art, NOAA
cannot assume liability for any damages caused by any errors or omissions in
the data, nor as a result of the failure of the data to function on a
particular system. NOAA makes no warranty, expressed or implied, nor does the
fact of distribution constitute such a warranty.
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Data Set Progress
Distribution Format: pdf
Fees: Data can be downloaded free of charge.
Role: DIF AUTHOR
Role: TECHNICAL CONTACT
Phone: (303) 497-6323
Fax: (303) 497-6513
Email: solar.ngdc at noaa.gov
325 Broadway E/GC2
Province or State: CO
Postal Code: 80305
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2015-11-16
Last DIF Revision Date: 2018-05-22