A Model for the Total Solar Irradiance Based on Active Region Decay

Crouch, A. D.; Charbonneau, Paul; Beaubien, Geneviève; Paquin-Ricard, Danahé

doi:10.1086/527433

Cited by 28 publications

(22 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We adopt the same value for the quiet Sun reference as in Paper II, i.e. 1365.46 W m −2 , which is very close to the average value found by Crouch et al (2008) with their TSI model over twelve solar cycles. Contrary to Paper II, we include in the procedure the influence of the centre-to-limb-darkening, so as to take into account the Claret limb-darkening law we will now use in our simulations.…”

Section: Spot and Bright Feature Contrast And Photometric Time Seriesmentioning

confidence: 68%

Using the Sun to estimate Earth-like planets detection capabilities

Borgniet

Meunier

Lagrange

2015

A&A

136

View full text Add to dashboard Cite

Context. Stellar activity induced by active structures such as stellar spots and faculae is known to have a strong impact on the radial velocity (RV) time series. It is therefore a strong limitation to the detection of small planetary RV signals, such as that of an Earth-mass planet in the habitable zone of a solar-like star. In a series of previous papers, we have studied the detectability of such planets around the Sun observed as a star in an edge-on configuration. For this purpose, we computed the RV, photometric and astrometric variations induced by solar magnetic activity, using all active structures observed over one entire cycle. Aims. Our goal is to perform similar studies on stars with different physical and geometrical properties. As a first step, we focus on Sun-like stars seen with various inclinations, and on estimating detection capabilities with future instruments. Methods. To do so, we first parameterize the solar active structures with the most realistic pattern so as to obtain results consistent with the observed ones. We simulate the growth, evolution and decay of solar magnetic features (spots, faculae and network), using parameters and empiric laws derived from solar observations and literature. We generate the corresponding structure lists over a full solar cycle. We then build the resulting spectra and deduce the RV and photometric variations, first in the case of a sun seen edge-on and then with various inclinations. The produced RV signal takes into account the photometric contribution of spots and faculae as well as the attenuation of the convective blueshift in faculae. We then use these patterns to study solar-like stars with various inclinations. Results. The comparison between our simulated activity pattern and the observed pattern validates our model. We show that the inclination of the stellar rotation axis has a significant impact on the photometric and RV time series. Radial velocity long-term amplitudes and short-term jitters are significantly reduced when going from edge-on to pole-on configurations. Assuming spin-orbit alignment, the best configuration for planet detection is an inclined star (i 45 • ).

show abstract

Section: Spot and Bright Feature Contrast And Photometric Time Seriesmentioning

confidence: 68%

Using the Sun to estimate Earth-like planets detection capabilities

Borgniet

Meunier

Lagrange

2015

A&A

136

View full text Add to dashboard Cite

show abstract

“…Although there are some differences in the fraction of the solar hemisphere covered by plage regions as evaluated for the three series, the difference to the result of Foukal (1996) is larger, in particular around the peak of solar cycle 19. This shows that caution is needed when using such data in variability models (e.g., Crouch et al 2008) without careful analysis of their problems and intrinsic instrumental variations.…”

Section: Discussionmentioning

confidence: 99%

COMPARISON AMONG Ca II K SPECTROHELIOGRAM TIME SERIES WITH AN APPLICATION TO SOLAR ACTIVITY STUDIES

Ermolli

Solanki

Tlatov

et al. 2009

ApJ

103

View full text Add to dashboard Cite

Various observatories around the globe started regular full-disk imaging of the solar atmosphere in the Ca ii K line in the early decades of the 20th century. The archives made by these observations have the potential of providing far more detailed information on solar magnetism than just the sunspot number and area records to which most studies of solar activity and irradiance changes are restricted. We evaluate the image quality and contents of three Ca ii K spectroheliogram time series, specifically those obtained by the digitization of the Arcetri, Kodaikanal, and Mt Wilson photographic archives, in order to estimate their value for studies focusing on timescales longer than the solar cycle. We analyze the quality of these data and compare the results obtained with those achieved for similar present-day observations taken with the Meudon spectroheliograph and with the Rome-PSPT. We also investigate whether image-segmentation techniques, such as those developed for identification of plage regions on present-day Ca ii K observations, can be used to process historic series. We show that historic data suffer from stronger geometrical distortions and photometric uncertainties than similar presentday observations. The latter uncertainties mostly originate from the photographic calibration of the original data and from stray-light effects. We also show that the image contents of the three analyzed series vary in time. These variations are probably due to instrument changes and aging of the spectrographs used, as well as changes of the observing programs. The segmentation technique tested in this study gives reasonably consistent results for the three analyzed series after application of a simple photographic calibration. Although the plage areas measured from the three analyzed series differ somewhat, the difference to previously published results is larger.

show abstract

“…Foukal & Lean 1988;Fligge et al 2000;Krivova et al 2003;Wang et al 2005;Crouch et al 2008). The Spectral and Total Irradiance REconstructions (SATIRE) set of models (Krivova et al 2011) are based on this assumption.…”

Section: Introductionmentioning

confidence: 99%

Reconstruction of spectral solar irradiance since 1700 from simulated magnetograms

Dasi-Espuig

Jiang

Krivova

et al. 2016

A&A

View full text Add to dashboard Cite

Aims. We present a reconstruction of the spectral solar irradiance since 1700 using the SATIRE-T2 (Spectral And Total Irradiance REconstructions for the Telescope era version 2) model. This model uses as input magnetograms simulated with a surface flux transport model fed with semi-synthetic records of emerging sunspot groups. Methods. The record of sunspot group areas and positions from the Royal Greenwich Observatory (RGO) is only available since 1874. We used statistical relationships between the properties of sunspot group emergence, such as the latitude, area, and tilt angle, and the sunspot cycle strength and phase to produce semi-synthetic sunspot group records starting in the year 1700. The semi-synthetic records are fed into a surface flux transport model to obtain daily simulated magnetograms that map the distribution of the magnetic flux in active regions (sunspots and faculae) and their decay products on the solar surface. The magnetic flux emerging in ephemeral regions is accounted for separately based on the concept of extended cycles whose length and amplitude are linked to those of the sunspot cycles through the sunspot number. The magnetic flux in each surface component (sunspots, faculae and network, and ephemeral regions) was used to compute the spectral and total solar irradiance (TSI) between the years 1700 and 2009. This reconstruction is aimed at timescales of months or longer although the model returns daily values. Results. We found that SATIRE-T2, besides reproducing other relevant observations such as the total magnetic flux, reconstructs the TSI on timescales of months or longer in good agreement with the PMOD composite of observations, as well as with the reconstruction starting in 1878 based on the RGO-SOON data. The model predicts an increase in the TSI of 1.2 +0.2 −0.3 Wm −2 between 1700 and the present. The spectral irradiance reconstruction is in good agreement with the UARS/SUSIM measurements as well as the Lyman-α composite.

show abstract

A Model for the Total Solar Irradiance Based on Active Region Decay

Cited by 28 publications

References 92 publications

Using the Sun to estimate Earth-like planets detection capabilities

Using the Sun to estimate Earth-like planets detection capabilities

COMPARISON AMONG Ca II K SPECTROHELIOGRAM TIME SERIES WITH AN APPLICATION TO SOLAR ACTIVITY STUDIES

Reconstruction of spectral solar irradiance since 1700 from simulated magnetograms

Contact Info

Product

Resources

About