J/A+A/710/L24 Reconstruction of annual solar irradiance (Temaj+, 2026)
Reconstruction of annual solar irradiance over the last three millennia.
Temaj D., Krivova N.A., Solanki S.K., Usoskin I.G., Chatzistergos T.
<Astron. Astrophys. 710, L24 (2026)>
=2026A&A...710L..24T 2026A&A...710L..24T (SIMBAD/NED BibCode)
ADC_Keywords: Sun ; Magnetic fields
Keywords: Sun: activity - Sun: heliosphere - Sun: magnetic fields -
solar-terrestrial relations
Abstract:
Solar irradiance measurements are limited, spanning only the last few
decades, requiring reconstructions to assess solar variability on
longer timescales and its impact on Earth's climate. We present the
first physics-based reconstruction of total solar irradiance (TSI) at
annual resolution over the last three millennia. The reconstruction is
obtained by extending the SATIRE-T model beyond the telescopic era
using recently published, annually resolved sunspot number series
derived from cosmogenic isotope records. This yields a continuous,
physics-based TSI record extending from the satellite era back over
the last three millennia, with an annual resolution throughout the
pre-telescopic period. Over this full interval, the reconstructed TSI
exhibits a maximum difference of 1.04-0.2+0.14 W/m2, defined as
the difference between the maximum and minimum of the 50-year running
mean values.
Description:
Total and spectral solar irradiance reconstructed using the SATIRE-T
model with the sunspot number derived from cosmogenic isotope data
(14C) as input. The data have annual resolution covering the period
997 BCE to 1899 CE. The upper and lower TSI bounds reflect the spread
obtained by driving the SATIRE model with the upper and lower bounds
of the 14C-based sunspot number reconstruction provided in the source
papers.
Description of file: TSI.fits
Total solar irradiance reconstruction
----------------------------------------------------------------------
Column Unit Description
----------------------------------------------------------------------
TIME yr Time in decimal years
TSI W/m2 Total Solar Irradiance (best estimate)
TSI_UPPER W/m2 Upper bound of TSI uncertainty range
TSI_LOWER W/m2 Lower bound of TSI uncertainty range
----------------------------------------------------------------------
Reading example in Python:
from astropy.io import fits
with fits.open('TSI.fits') as hdul:
data = hdul['TSI'].data
time = data['TIME']
tsi = data['TSI']
tsi_upper = data['TSI_UPPER']
tsi_lower = data['TSI_LOWER']
--------------------------------------------------------------------------------
Description of file: SSI.fits
Spectral solar irradiance reconstruction
----------------------------------------------------------------------
Extension Type Dimensions Description
----------------------------------------------------------------------
SSI ImageHDU (time, 1070) Spectral Solar Irradiance
WAVELENGTH ImageHDU (1070,) Wavelength array
TIME ImageHDU (time,) Time array
----------------------------------------------------------------------
Column Unit Description
----------------------------------------------------------------------
SSI W/m2/nm Spectral Solar Irradiance as a function of
time and wavelength (best estimate)
WAVELENGTH nm Wavelength array
TIME yr Time in decimal years
----------------------------------------------------------------------
Reading example in Python:
from astropy.io import fits
with fits.open('SSI.fits') as hdul:
ssi = hdul['SSI'].data.copy() # (time, wavelength)
wavelength = hdul['WAVELENGTH'].data.copy() # (1070,)
time = hdul['TIME'].data.copy() # (time,)
--------------------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 73 2 List of fits files (corrected versions, 15-Jul-2026)
fits/* . 2 Individual files (corrected versions, 15-Jul-2026)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 I7 --- Nx Number of pixels along X-axis
9- 15 I7 --- Ny Number of pixels along Y-axis
17- 23 I7 Kibyte size Size of FITS file
25- 32 A8 --- FileName Name of FITS file, in subdirectory fits
34- 73 A40 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Duresa Temaj, duresa.temaj(at)gmail.com
License: CC-BY-4.0
History:
16-Jun-2026: on-line version
15-Jul-2026: corrected fits files
(End) Patricia Vannier [CDS] 20-May-2026