Accession Number:

AD1089381

Title:

Modeling Solar Irradiance Variability and the Ionospheric Response to Solar Flares

Descriptive Note:

Technical Report,30 Apr 2018,30 Apr 2019

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC WASHINGTON United States

Personal Author(s):

• Reep,Jeffrey W.
• Warren,Harry P.
• Crump,Nicholas A.
• Knizhnik,Kalman J.
• Bradshaw,Stephen J.

Report Date:

2019-12-17

Pagination or Media Count:

22.0

Abstract:

We developed a model to synthesize irradiance from a detailed hydrodynamic model of a solar flare. The model was developed to accurately calculate the details of the solar chromosphere, which is characterized by non-local thermodynamic equilibrium, necessitating a radiative transfer calculation. A method to solve this efficiently was implemented, tested against other models, and validated against observations of the chromosphere with data taken by NASAs IRIS satellite. We developed a multi-threaded model of a solar flare, accounting for the time-varying geometry, large number of loop structures, and time varying energy release. The parameters of this model were derived using data from NOAAs GOES satellite to determine heating rates and volumes for flares. Using this global model, we synthesized X-ray spectra that are then validated against an X-ray spectrometer for a set of five observed flares. These synthetic spectra are being developed for delivery to ionospheric general circulation models to calculate the impact of extreme flares on the Earth.

Descriptors:

• electron beams
• ionosphere
• radiation
• x ray spectra
• radiative transfer
• solar flares
• space sciences
• spectral lines
• electrons
• ionization
• solar atmosphere
• solar physics
• x rays

Subject Categories:

• Astrophysics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE