SLIDE 1 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
SLIDE 2 Solar Wind CMEs Electromagnetic emission in different wavelengths: SSI and TSI
Sun’s dynamics
Earth’s atmosphere
HMI data
ARs Coronal Holes (CHs)
SLIDE 3
Solar Spectral Irradiance (SSI) and Earth’s atmosphere
Ionosphere EUV - Satellite communication-GPS EUV - chemistry Stratosphere The SSI variation at EUV wavelengths has important consequences for the Earth’s upper atmosphere because the SSI is completely absorbed into the tenuous layers above the stratosphere (Schöll et al. 2016; Fontenla et al. 2017)
SLIDE 4 COronal DEnsity and Temperature 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
SLIDE 5 COronal DEnsity and Temperature model
Rodríguez Gómez et al. 2018 Search the best fit parameters
SLIDE 6
Solar magnetic field data
MDI data HMI data
SLIDE 7 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
SLIDE 8 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
SLIDE 9 Density and temperature profiles description
Density profile Temperature profile Bth function
SLIDE 10 Density and temperature profiles description
Density profile Temperature profile Bth function Model parameters
SLIDE 11 Emission Model
- Based on the contribution function G(𝜇,T), instrumental response R(𝜇), spectral resolution d𝜇
, 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
1AU
SLIDE 12 Emission Model
The intensity I is the full-disc average intensity measured at Earth from an emission line, where D = 1AU
1AU
SLIDE 13
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
SLIDE 14 Rodríguez Gómez et al. 2018
Optimization algorithm- Genetic algorithm pikaia
SLIDE 15 CODET Model Parameters
Rodríguez Gómez et al. 2018
Imodel SSI from CODET Iobs SSI from TIMED/SEE
SLIDE 16 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
- bservational and model descriptions (Billings 1966; Withbroe 1988; Aschwanden
2005; Golub & Pasachoff 2009; Habbal et al. 2010; Fontenla et al. 2014)
CODET Model Parameters
SLIDE 17
- 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
Main Results
SLIDE 18
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
SLIDE 19
The transition region demarcates the boundary where the chromospheric temperature increases and the density drops
SLIDE 20 Rodríguez Gómez et al. 2018
SSI - EUV band
Ciclo solar 23 Ciclo solar 24
SLIDE 21 Rodríguez Gómez et al. 2018
SLIDE 22
- 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
Next steps
SLIDE 23
Thank you!
jemfisi@gmail.com jenny.gomez@inpe.br
