J/A+A/645/A2 Solar spectral irradiance during Solar Cycle 24 (Meftah+, 2021)
SOLAR-v: A new solar spectral irradiance dataset based on SOLAR/SOLSPEC
observations during Solar Cycle 24.
Meftah M., Snow M., Dame L., Bolsee D., Pereira N., Cessateur G., Bekki S.,
Keckhut P., Sarkissian A., Hauchecorne A.
<Astron. Astrophys. 645, A2 (2021)>
=2021A&A...645A...2M 2021A&A...645A...2M (SIMBAD/NED BibCode)
ADC_Keywords: Sun ; Spectra, ultraviolet
Keywords: Sun: general - Sun: fundamental parameters - Sun: UV radiation -
solar-terrestrial relations
Abstract:
Solar spectral irradiance (SSI) is the wavelength-dependent energy
input to the top of the Earth's atmosphere. Solar ultraviolet (UV)
irradiance represents the primary forcing mechanism for the
photochemistry, heating, and dynamics of the Earth's atmosphere.
Hence, both temporal and spectral variations in solar UV irradiance
represent crucial inputs to the modeling and understanding of the
behavior of the Earth's atmosphere. Therefore, measuring the
long-term solar UV irradiance variations over the 11-year solar
activity cycle (and over longer timescales) is fundamental. Thus, each
new solar spectral irradiance dataset based on long-term observations
represents a major interest and can be used for further investigations
of the long-term trend of solar activity and the construction of a
homogeneous solar spectral irradiance record.
The main objective of this article is to present a new solar spectral
irradiance database (SOLAR-v) with the associated uncertainties. This
dataset is based on solar UV irradiance observations (165-300nm) of
the SOLAR/SOLSPEC space-based instrument, which provides measurements
of the full-disk SSI during solar cycle 24.
SOLAR/SOLSPEC made solar acquisitions between April 5, 2008 and
February 10, 2017. During this period, the instrument was affected by
the harsh space environment that introduces instrumental trends
(degradation) in the SSI measurements. A new method based on an
adaptation of the Multiple Same-Irradiance-Level (MuSIL) technique was
used to separate solar variability and any uncorrected instrumental
trends in the SOLAR/SOLSPEC UV irradiance measurements.
A new method for correcting degradation has been applied to the
SOLAR/SOLSPEC UV irradiance records to provide new solar cycle
variability results during solar cycle 24. Irradiances are reported at
a mean solar distance of 1 astronomical unit (AU). In the 165-242nm
spectral region, the SOLAR/SOLSPEC data agrees with the observations
(SORCE/SOLSTICE) and models (SATIRE-S, NRLSSI 2) to within the 1-sigma
error envelope. Between 242 and 300nm, SOLAR/SOLSPEC agrees only with
the models.
Description:
The SOLAR/SOLSPEC Solar Spectral Irradiance (SSI) data product is
constructed using measurements from the SOLAR/SOLSPEC instrument
(low time resolution) and the SATIRE-S model (data reconstruction to
fill the gaps of SOLAR/SOLSPEC observations), which are combined into
merged daily solar spectra over the spectral intervals shown in the
table below.
Irradiances are reported at a mean solar distance of 1AU.
SELECTION CRITERIA:
date range: 20080405 to 20170210
cadence: 24 hours (daily)
spectral range: 165.0 to 3000.0 nm
number of data: 2396394
identifierproductdoi (CDS): XXXX.XXXX.XX
identifierproductdoi_authority (CDS): http://dx.doi.org/
DATA DEFINITIONS:
number = 6 (name, type, format)
nominaldateyyyy-mm-dd
nominal_time
wavelength bin lower bound, f12.2 (nm)
wavelength bin upper bound, f12.2 (nm)
spectral solar irradiance, e12.6 (W/m2/nm^)
irradiance_uncertainty, f12.8 (unitless, 1 sigma)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
data.dat 84 2396394 SOLAR/SOLSPEC solar spectral irradiance during
Solar Cycle 24
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See also:
VI/152 : SOVAP-PICARD total solar irradiance (Meftah+, 2016)
J/A+A/531/A6 : Evolution of solar irradiance during Holocene (Vieira+, 2011)
J/A+A/581/A26 : Solar Lyman irradiance line profiles (Lemaire+, 2015)
J/ApJ/789/117 : Solar spectral irradiance (Marchenko+, 2014)
J/A+A/611/A1 : SOLAR/SOLSPEC Spectral Irradiance - 0.5-3000nm (Meftah+, 2018)
J/A+A/624/A36 : EUV irradiances of the quiet Sun (Del Zanna, 2019)
J/other/SoPh/291.3527 : SOLAR/SOLSPEC UV SSI from 2008-2015 (Meftah+, 2016)
Byte-by-byte Description of file (#): data.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "YYYY-MM-DD" Obs.date Observation date
12- 19 A8 "h:m:s" Obs.time Observation time
30- 36 F7.2 nm blambda Wavelength bin lower bound
46- 52 F7.2 nm Blambda Wavelength bin upper bound
57- 68 E12.7 W/m2/nm SSI Spectral solar irradiance
75- 84 F10.8 --- e_SSI Irradiance uncertainty (unitless, 1 sigma)
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Acknowledgements:
Mustapha Meftah, mustapha.meftah(at)latmos.ipsl.fr
This work is based on observations with SOLAR/SOLSPEC embarked onboard
the international space station. We are grateful to the instrument
teams for providing their public data products for this study.
(End) Patricia Vannier [CDS] 02-Nov-2020