UARS SOLSTICE Level 3BS Solar UV Irradiance Spectra V001 (UARSO3BS) at GES DISCEntry ID: GES_DISC_UARSO3BS_V001
Abstract: The Solar-Stellar Irradiance Comparison Experiment (SOLSTICE) on
NASA's Upper Atmosphere Research Satellite (UARS) measured the energy
input to the upper atmosphere by observing the solar spectral
irradiance in the ultraviolet spectral range from 119 to 420 nm. The
SOLSTICE measured the full disk solar irradiance with high precision
and ... accuracy to follow short-term (minutes to hours),
intermediate-term (days to weeks), and long-term (11 year sunspot, and
22 year solar magnetic field cycles) variations in the solar output.
The SOLSTICE instrument is a three-channel ultraviolet spectrometer that
measures the magnitude of solar and spectral irradiance in the wavelength
range form 119 to 420 nm. The design of the instrument allows for observations
of both the sun and bright blue stars (whose spectra in the SOLSTICE spectral
range is assumed to be constant) using the same optics. The entrance and exit
slit sizes are varied, and different integration times are used to accommodate
the 5 to 8 order of magnitude difference between the brightnesses of the sun
and blue stars.
SOLSTICE is mounted to the two-axis Solar Stellar Pointing Platform
(SSPP) which can track objects to an accuracy of 1.5 arc minutes.
During the daylight portion of an orbit SOLSTICE is pointed at the
sun, and during the nighttime portion it is pointed toward blue stars.
One or more full spectral scans of the sun at the instrument
resolution is completed each orbit. Stellar scans require longer
integration times, and are only made at a few selected wave- lengths
throughout the spectral range, with typically one or two stars at one
or two wavelengths being observed each orbit.
Two SOLSTICE Level 3 data products are produced each day: Level 3AS,
and Level 3BS. The Level 3AS format is common to all UARS solar instruments.
The Level 3BS format is identical to the Level 3AS format, except that
instrument degradation is included in the 3BS data products.
SOLSTICE_L3AS_DAILY: These data products contain a single array
representing a daily mean solar spectrum. Each element in the array
is spaced at 1.0 nm intervals and centered on the half nm from 115 to
420 nm. The array elements have been normalized to an earth-sun
distance of 1 AU. Also produced, as Level 3AS parameters, are daily
average integrated intensities (Gaussian fits) or core/wing ratios
(Mg-II at 280 nm and Ca-II at 393 nm) for selected solar spectral
SOLSTICE_L3BS_DAILY: These data products are produced from the
corresponding Level 3AS data product, and a table (calibration file)
of instrument degradation function coefficients which have been
determined from selected bright blue stars. The time-degradation
function (which varies with wavelength) is applied to the Level 3AS
irradiance spectrum and the integrated irradiance of the selected
spectral emission features, but not to the core/wing ratios, to
produce the Level 3BS data products.
* NOTE: only SOLSTICE_L3BS_DAILY data are available from the GSFC DAAC.
Data Set Citation
Dataset Originator/Creator: NASA UARS/SOLSTICE
Dataset Title: UARS Solar-Stellar Irradiance Comparison Experiment (SOLSTICE) Level 3BS
Version: 001Online Resource: http://mirador.gsfc.nasa.gov/cgi-bin/mirador/presentNavigation.pl?t...
Start Date: 1991-10-03Stop Date: 1999-12-31
Latitude Resolution: ultraviolet spectral range from 119 to 420 nm
Longitude Resolution: ultraviolet spectral range from 119 to 420 nm
Horizontal Resolution Range: < 1 meter
ATMOSPHERE > ATMOSPHERIC RADIATION > SOLAR IRRADIANCE
ATMOSPHERE > ATMOSPHERIC RADIATION > SOLAR RADIATION
ATMOSPHERE > ATMOSPHERIC RADIATION > ULTRAVIOLET RADIATION
SPECTRAL/ENGINEERING > ULTRAVIOLET WAVELENGTHS > ULTRAVIOLET FLUX
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SOLAR ACTIVE REGIONS
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SOLAR IRRADIANCE
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SOLAR ULTRAVIOLET EMISSIONS
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SUNSPOTS
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SOLAR SYNOPTIC MAPS
ISO Topic Category
Role: DIF AUTHOR
Email: James.Johnson at nasa.gov
NASA Goddard Space Flight Center Code 610.2
Province or State: MD
Postal Code: 20771
Phone: (303) 492-8324
Email: Gary.Rottman at lasp.colorado.edu
Laboratory for Atmospheric and Space Physics University of Colorado
Province or State: CO
Postal Code: 80303
Rottman, G. J. and Woods, T. N., 'In-Flight Calibration of Solar Irradiance
Measurements by Direct Comparison with Stellar Observations', SPIE
Procedings, 924, 136-143, 1988.
Rottman, G. J., Woods, T. N., and Sparn, T. P., 'Solar-Stellar Irradiance
... Comparison Experiment 1. 1. Instrument Design Operation', J. Geophys.
Res. 98, D6, 10667-10677, 1993.
Woods, T. N., Rottman, G. J., and G. J. Ucker, 'Solar-Stellar Irradiance
Comparison Experiment 1. 2. Instrument Calibrations',
J. Geophys. Res. 98, D6, 10679-10694, 1993.
Reber, C. A., C. E. Trevathan, R. J. McNeal, and M. R. Luther, 'The Upper
Atmosphere Research Satellite (UARS) Mission', J. Geophys. Res. 98, D6,
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2006-12-29
Last DIF Revision Date: 2009-08-21