This is an IDL version of the GLOW model (https://www2.hao.ucar.edu/modeling/glow/code)\ All assumptions and assumed parameters (e. g. cross sections) are the same. In most cases the procedures were developed to take advantage of IDL's simplified programming structure. A couple procedures are directly converted from the Fortran. The purpose of these codes is to allow GLOW to be more easily used by students in aeronomy classes. It has been compared to GLOW and compares well and so is fine for research purposes, though much slower. Some issues at low energy (<10 eV) exist because of a more simple empirical description of the thermal electron density.
The main modules in the ACE-PE model are:
ace_common_blocks.prg- Common block for the PE model\
localpe_setup_pxsect.pro - Calculates the photoionization cross-sections of the major species O,O2 and N2
localpe_setup_exsect.pro - Calculates the electron impact excitation cross-sections
ace_setup_elasticx.pro - This procedure uses tabulated values of elastic cross section parameters for o, o2, and n2 and places them onto the chosen energy grid
localpe_neutralatm.pro - calculates the netral density and colum densities of the N2, O2 and O
localpe_approxden.pro
localpe_ssflux.pro- Contains the input solar flux data
localpe_photoionz.pro- Calculates the photoionizaiton rates of major species
localpe.pro- Local calculation for photoelectron rates of major species
ace_etransport.pro- Trasnport calculation for photoelectron rates of major species using two-stream approach, based on GLOW model two-stream transport calulation \
Important model parameters:
nmaj: number of major species
nbins: number of electron energy levels
nei: number of energy levels
nst: number of electronic excitation states
jmax : number of altitudes
lmax : number of solar flux bins
tpot : threshold energy (eV) of photoionization of different ionization states of major species
prob :branching probability of photoionization of major species
primary: primary photoelectron ionization rate (cm-3 s-1)\
wv1: Solar flux wavelength (lower bound )
wv2: Solar flux wavelength (upper bound )
ssflux: Solar flux
sigabs: Photoabsorption cross-section (cm2)
sigionx: : Photoabsorption cross-section (cm2)
auger_energy: Auger Energy (eV) for major species
auger_wvln: : Auger Wavelength for major species\
Electron Impact Cross-sections:
sigloss: sigloss total loss cross section (cm2),i.e., production and loss due to cascade in energy through ionization & excitation and production of secondaries
through ionization
sec: cross section for cascade forming PE with lower energy by PE with higher energy and collisions (ionization) with species, cm^2
siga: cross section for energy loss by PE of higher energy to PE of lower energy through collisions (ionizatin & excitation) with species, cm^2
sigex: excitation cross-section for each state, species, energy; cm2
sigix: ionization cross-section for each state, species, energy; cm2\
upflux: Upward Photoelectron flux (cm-2 s-1 eV-1)
downflux: Downward Photoelectron flux (cm-2 s-1 eV-1)
tflux: Total Photoelectron flux (cm-2 s-1 eV-1); from transport calculation
pespec: Total Photoelectron flux (cm-2 s-1 eV-1); from local calculation
zmaj:Number density of major species cm-3
zz: Altitude in km
lat: Latitude in degrees
lon: : Longitude in degrees
sza: Solar Zenith angle in radians
idate: Date yyyydoy
utsec: Universal Time in seconds
f107: F10.7 daily index
f107a: F10.7 81-day average index
ap: Ap index
zcol: Column density (cm-2) of major species
tau: Optical depth
eden: Electron Density (cm-3)
etemp: ELectron Temperature (K)
eiionz:Local electron impact ionozation rates(species,altitude) (cm-3 s-1)
eiionzk:Local electron impact ionozation rates(states,species,altitude) (cm-3 s-1) \
eiionz_transp::Trasnport electron impact ionozation rates(species,altitude) (cm-3 s-1)
eiionzk_transp:Transport electron impact ionozation rates(states,species,altitude) (cm-3 s-1)\
exct_transp:Transport electron impact excitation rates(states,species,altitude) (cm-3 s-1)
exct_local:Local electron impact excitation rates(states,species,altitude) (cm-3 s-1)\
sigs: elastic cross sections for each species, energy; cm2
PE: elastic backscatter probabilities for each species, energy
PI: inelastic backscatter probabilities for each species, energy\
WW: energy threshold for each excited state, species; eV
THI: energy threshold for each ionized state, species; eV
ener: electron energy grid; eV
del: electron energy grid spacing; eV
NNN: number of excited states for each species
NINN: number of ionized states for each species
NUM: number of points on elastic data trid for each species
EC: data energy grid of elastic xsects and backscatter ratios for each species; eV
CC: elastic cross-sections on data grid for each species, cm2
CE: elastic backscat. probs on data grid for each species; cm2
CI: inelastic backscat. probs on data grid for each species; cm2\
Sample run for the PE model given in sample_localpe_v6.pro\