J/ApJS/261/17 MgII h & k profiles over the solar cycle with IRIS (Koza+, 2022)
Data-driven model of temporal evolution of solar MgII h and k profiles over the
solar cycle.
Koza J., Gunar S., Schwartz P., Heinzel P., Liu W.
<Astrophys. J. Suppl. Ser., 261, 17 (2022)>
=2022ApJS..261...17K 2022ApJS..261...17K
ADC_Keywords: Sun; Ultraviolet
Keywords: Solar chromosphere ; Solar ultraviolet emission ; Solar cycle
Abstract:
The solar radiation in the cores of the MgII h and k spectral lines
plays a significant role in the illumination of prominences, coronal
mass ejections (CMEs), spicules, flare loops, and surges. Moreover,
the radiation in these lines strongly correlates with solar magnetic
activity and the ultraviolet solar spectral irradiance affecting the
photochemistry, especially of oxygen and nitrogen, in the middle
atmosphere of the Earth. This work provides a data-driven model of
temporal evolution of the solar full-disk MgII h and k profiles over
the solar cycle. The capability of the model to reproduce the MgII h
and k profiles for an arbitrary date is statistically assessed. Based
on selected 76 IRIS near-UV full-Sun mosaics covering almost the full
solar cycle 24, we find the parameters of double-Gaussian fits of the
disk-averaged MgII h and k profiles and a model of their temporal
evolution parameterized by the Bremen composite MgII index. The model
yields intensities within the uncertainties of the observed data in
more than 90% of the reconstructed profiles assuming a statistically
representative set of Bremen MgII index values in the range of
0.150-0.165. The relevant full-disk MgII h and k calibrated profiles
with uncertainties and spectral irradiances are provided as an online
machine-readable table. The model yields MgII h and k profiles
representing the disk incident radiation for the radiative-transfer
modeling of prominences, CMEs, spicules, flare loops, and surges
observed at arbitrary time.
Description:
At the time of writing, the archive of the Interface Region Imaging
Spectrograph (IRIS) full-Sun mosaics contained 105 observations
spanning the period from 2013 September 30 to 2022 May 30 with the
number of mosaics per year as follows: 2013 (4 mosaics), 2014 (10),
2015 (13), 2016 (14), 2017 (11), 2018 (11), 2019 (14), 2020 (14),
2021 (10), and 2022 (4).
In this paper we utilize the same data in Paper I
(Gunar+ 2021, J/ApJS/255/16), i.e., 91 mosaics spanning the period
from 2013 September 30 to 2020 October 19. Details on observational
characteristics of the mosaics, their processing, their radiometric
calibration, and their uncertainties can be found in Paper I.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 70 9191 Specific intensities and spectral irradiances of
disk-averaged MgII h and k profiles; selected
characteristics of IRIS full-Sun mosaics
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See also:
J/A+A/390/717 : Solar Vel. of the Sun in 1989-99 (IRIS++) (Salabert+, 2002)
J/A+A/423/1109 : Center-to-limb variation of quiet Sun (Allende+, 2004)
J/A+A/432/1063 : Analysis of inner solar corona in EUV (Lanzafame+, 2005)
J/ApJS/213/11 : UV spectrum of the quiet Sun above the limb (Warren+, 2014)
J/A+A/624/A36 : EUV irradiances of the quiet Sun (Del Zanna, 2019)
J/A+A/644/A109 : Quiet-sun hydrogen Lyman-alpha line profile (Gunar+, 2020)
J/ApJ/897/L10 : Disturbance storm time index (Hayakawa+, 2020)
J/ApJS/255/16 : Quiet-Sun MgII h & k line profiles from IRIS (Gunar+, 2021)
http://lasp.colorado.edu/lisird/ : LASP interactive solar irradiance data
center home page
http://iris.lmsal.com/mosaic_index.html : IRIS full-disk mosaics index
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/91] IRIS mosaic number
4- 7 I4 yr Obs.Y [2013/2020] Observation Year
8- 9 I2 "month" Obs.M Observation Month
10- 11 I2 d Obs.D Observation Day
13- 19 F7.4 nm delLam [-0.175/0.175] Wavelength separation (1)
21- 25 F5.0 W/m2/sr/nm I1 [375/2999] Specific intensity of MgII h
27- 30 F4.2 10-10W/m2/sr/Hz I2 [0.98/7.9] Specific intensity of MgII h,
in 10-7erg/s/cm2/sr/Hz units
32- 37 F6.2 mW/m2/nm Ee1 [25.47/204] Spectral irradiance of MgII h
39- 41 F3.0 % sigma1 [2/59] Percent uncertainty in I1, I2,
and Ee1
43- 47 F5.0 W/m2/sr/nm I3 [252/3806] Specific intensity of MgII k
49- 52 F4.2 10-10W/m2/sr/Hz I4 [0.66/10] Specific intensity of MgII k,
in 10-7erg/s/cm2/sr/Hz units
54- 59 F6.2 mW/m2/nm Ee2 [17/259] Spectral irradiance of MgII k
61- 63 F3.0 % sigma2 [2/88] Percent uncertainty in I3, I4,
and Ee2
65 I1 --- Bin [2/4] Spatial and spectral binning
67- 68 F2.0 s texp [1/8] Exposure time
70 I1 --- Ref [0/1] Flag for non-reference and
reference mosaic, respectively (2)
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Note (1): From the rest wavelengths of the MgII h and k lines.
Note (2): The 12 IRIS NUV "reference mosaics" which represent days without
sunspots or other significant signs of solar activity are given in
Paper I (Gunar+ 2021, J/ApJS/255/16), section 2.2: 2019 April 21,
May 27, July 27, September 12, 22, and October 20; 2020 March 2, 23,
April 22, June 21, August 23, and September 6.
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History:
From electronic version of the journal
References:
Gunar et al. Paper I. 2021ApJS..255...16G 2021ApJS..255...16G Cat. J/ApJS/255/16
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 22-Sep-2022