Solar Spectral Irradiance (SSI) from CODET model and their relation with Earth’s upper atmosphere Jenny Marcela Rodríguez Gómez PhD in Space Geophysics (INPE) Collaborators: Luis Eduardo Antunes Vieira Alisson Dal Lago Judith Palacios April 25-2018
Sun’s dynamics Earth’s atmosphere Solar Wind ARs CMEs Electromagnetic emission in different wavelengths: SSI Coronal Holes and TSI (CHs) HMI data
Solar Spectral Irradiance (SSI) and Earth’s atmosphere Ionosphere The SSI variation at EUV EUV - Satellite wavelengths has important communication-GPS consequences for the Earth’s upper atmosphere because the SSI is completely absorbed into the tenuous layers above the stratosphere (Schöll et al. Stratosphere 2016; Fontenla et al. 2017) EUV - chemistry
CO ronal DE nsity and T emperature model The COronal DEnsity and Temperature (CODET) model is based on the assumption that the variation of the irradiance and plasma parameters is due to the evolution of the solar magnetic field. Ingredients ● Flux transport model ● Density and temperature model ● Emission model ● We do not use MHD approximation
CO ronal DE nsity and T emperature model Search the best fit parameters Rodríguez Gómez et al. 2018
Solar magnetic field data HMI data MDI data
Flux transport model of Schrijver (2003) ● MDI and HMI data are assimilated into the flux transport model to describe the dynamics of the solar photosphere ● The model is sampled every six hours from 1996 July 1 ● These data are then used as boundary conditions for a series of potential field source- surface (PFSS) Rodríguez Gómez et al. 2018
Potential Field Source Surface (PFSS) model ● Current-free corona ● Synoptic maps of the photospheric magnetic field ● Extrapolate the line-of-sight surface magnetic field from 1.0Rsun to 2.5Rsun
Density and temperature profiles description Density profile Bth function Temperature profile
Density and temperature profiles description Density profile Model parameters Bth function Temperature profile
Emission Model 1AU Based on the contribution function G( 𝜇 ,T), instrumental response R( 𝜇 ), spectral resolution d 𝜇 ● , different distance along of line-of sight ds ● Chianti atomic database 8.0, ionization equilibrium (Mazzotta et al. 1998) and coronal abundances (Meyer 1985) model
Emission Model 1AU The intensity I is the full-disc average intensity measured at Earth from an emission line, where D = 1AU
Optimization algorithm- Genetic algorithm pikaia Biological processes - the natural selection. Charbonneau (1995) The population of individuals (parameters) is chosen at random range They are surveyed to determine their goodness-of-fit A new generation of individuals is generated Their characteristics are passed on to the next generation
Optimization algorithm- Genetic algorithm pikaia Rodríguez Gómez et al. 2018
CODET Model Parameters I model SSI from CODET I obs SSI from TIMED/SEE Rodríguez Gómez et al. 2018
CODET Model Parameters The characteristics evaluated in each case were (1) goodness-of-fit between SSI from TIMED/SEE and modeled data; (2) electron density and temperature profiles according to observational and model descriptions (Billings 1966; Withbroe 1988; Aschwanden 2005; Golub & Pasachoff 2009; Habbal et al. 2010; Fontenla et al. 2014)
Main Results ● Solar Spectral Irradiance (SSI) in EUV band at 19.5 nm and 21.5 nm during the solar cycle 23 and 24 ● Emission maps through the solar atmosphere ● Temperature and density profiles during the solar cycle 23 and 24
Density and Temperature profiles through the solar atmosphere Temperature profile (left panel) and density profile (right panel) through the solar atmosphere on Dec. 15 (2001); specifically from R = 1Rsun to R = 2.5Rsun, for the parameter combinations shown in Table 1
The transition region demarcates the boundary where the chromospheric temperature increases and the density drops
SSI - EUV band Ciclo solar 23 Ciclo solar 24 Rodríguez Gómez et al. 2018
Rodríguez Gómez et al. 2018
Next steps ● The reconstruction of the solar spectral irradiance in near-real time ● Flux transport model (sampled < six hours) ● Include UV and other wavelengths Use in: ● Ionosphere models ● Climate models More details about the model are available in Rodríguez Gómez et al. 2018 ApJ
Thank you! jemfisi@gmail.com jenny.gomez@inpe.br
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