J/A+A/611/A1     SOLAR/SOLSPEC Spectral Irradiance - 0.5-3000nm  (Meftah+, 2018)
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SOLAR-ISS, a new reference spectrum based on SOLAR/SOLSPEC observations.
    Meftah M., Dame L., Bolsee D., Hauchecorne A., Pereira N., Sluse D.,
    Cessateur G., Irbah A., Bureau J., Weber M., Bramstedt K., Hilbig T.,
    Thieblemont R., Marchand M., Lefevre F., Sarkissian A., Bekki S.
    <Astron. Astrophys. 611, A1 (2018)>
    =2018A&A...611A...1M        (SIMBAD/NED BibCode)
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ADC_Keywords: Sun ; Spectra, ultraviolet
Keywords: Sun: fundamental parameters - Sun: general

Abstract:
    Since April 5, 2008 and up to February 15, 2017, the SOLar
    SPECtrometer (SOLSPEC) instrument of the SOLAR payload on board the
    International Space Station (ISS) has performed accurate measurements
    of solar spectral irradiance (SSI) from the middle ultraviolet to the
    infrared (165 to 3088nm). These measurements are of primary
    importance for a better understanding of solar physics and the impact
    of solar variability on climate. In particular, a new reference solar
    spectrum (SOLAR-ISS) is established in April 2008 during the solar
    minima of cycles 23-24 thanks to revised engineering corrections,
    improved calibrations, and advanced procedures to account for thermal
    and aging corrections of the SOLAR/SOLSPEC instrument.

    The main objective of this article is to present a new high-resolution
    solar spectrum with a mean absolute uncertainty of 1.26% at 1{sigma}
    from 165 to 3000nm. This solar spectrum is based on solar
    observations of the SOLAR/SOLSPEC space-based instrument.


    The SOLAR/SOLSPEC instrument consists of three separate double
    monochromators that use concave holographic gratings to cover the
    middle ultraviolet (UV), visible (VIS), and infrared (IR) domains. Our
    best ultraviolet, visible, and infrared spectra are merged into a
    single absolute solar spectrum covering the 165-3000nm domain. The
    resulting solar spectrum has a spectral resolution varying between 0.6
    and 9.5nm in the 165-3000nm wavelength range. We build a new solar
    reference spectrum (SOLAR-ISS) by constraining existing
    high-resolution spectra to SOLAR/SOLSPEC observed spectrum. For that
    purpose, we account for the difference of resolution between the two
    spectra using the SOLAR/SOLSPEC instrumental slit functions.

    Using SOLAR/SOLSPEC data, a new solar spectrum covering the 165-3000nm
    wavelength range is built and is representative of the 2008 solar
    minimum. It has a resolution better than 0.1nm below 1000nm and 1nm
    in the 1000-3000nm wavelength range. The new solar spectrum
    (SOLAR-ISS) highlights significant differences with previous solar
    reference spectra and with solar spectra based on models. The integral
    of the SOLAR-ISS solar spectrum yields a total solar irradiance of
    1372.3+/-16.9W/m^2^ at 1{sigma}, that is yet 11W/m^2^ over the value
    recommended by the International Astronomical Union in 2015.

Description:
    The SOLAR/SOLSPEC space-based instrument has measured the solar
    spectral irradiance from 165 to 3000nm at 0.6 to 9.5nm spectral
    resolution during the almost nine years of the SO- LAR/ISS mission.
    The instrument was calibrated using the PTB standard blackbody
    developed for temperatures up to 3200K. The absolute accuracy, based
    on a detailed analysis of error sources, indicates a mean absolute
    uncertainty of 1.26% of the total solar irradiance in the 165-3000nm
    range. Using SOLAR/SOLSPEC data, a new solar spectrum (SOLAR-ISS)
    covering the 165-3000nm wavelength range is built with added high
    spectral resolution. This SOLAR-ISS spectrum is developed by
    combining high spectral resolution from reference solar spectra with
    the resulting SOLAR/SOLSPEC spectrum through the knowledge of the slit
    functions of the SOLAR/SOLSPEC instrument.

File Summary:
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 FileName      Lrecl  Records   Explanations
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ReadMe            80        .   This file
spectrum.dat      44    48581  *SOLAR-ISS spectrum, Version: 1.1,
                                 Date: 18-October-2017
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Note on spectrum.dat: SOLAR/SOLSPEC Spectral Irradiance - 0.5-3000nm,
   Reference: April 2008 solar minimum.
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See also:
 J/A+A/531/A6    : Evolution of solar irradiance during Holocene (Vieira+, 2011)
 J/AJ/112/2274   : Spectral irradiance calibration. VII. (Cohen+ 1996)
 J/AJ/112/241    : Spectral irradiance calibration. VI. (Cohen+ 1996)
 J/ApJ/789/117   : Solar spectral irradiance (Marchenko+, 2014)
 J/A+A/562/A133  : Irradiated atmospheres analytical model (Parmentier+, 2014)
 J/A+A/574/A35   : Irradiated atmospheres analytical model (Parmentier+, 2015)
 J/A+A/581/A26   : Solar Lyman irradiance line profiles (Lemaire+, 2015)
 J/other/SoPh/291.3527 : SOLAR/SOLSPEC UV SSI from 2008-2015 (Meftah+, 2016)

Byte-by-byte Description of file: spectrum.dat
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   Bytes Format Units     Label     Explanations
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   1- 13  F13.8 nm        lambda    Wavelength
  19- 28  F10.8 W/m2/nm   SSI       ?=- Solar spectral irradiance
  34- 44  F11.8 %       e_SSI       ?=- Uncertainty on SSI (k=1)
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Acknowledgements:
    Mustapha Meftah, Mustapha.Meftah(at)latmos.ipsl.fr

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(End)                                        Patricia Vannier [CDS]  20-Oct-2017
