Quoted from: https://ccmc.gsfc.nasa.gov/models/models_at_glance.php

Model Description
The ABsorption BY the D and E Region of HF Signals
with NORMAL Incidence or the ABBYNORMAL Model calculates the D and E region (60-150 km) ionization sources and ion-neutral chemistry to obtain an electron density profile. The physics-based models within AbbyNormal are identical to the Data-Driven D-Region model (DDDR), which was created under NASA/Living-with-a-Star funding (NASW-02108). The AbbyNormal Model (DDDR) has simplified D region chemistry. The number of minor neutral and ion species used within the DDDR is small compared to the enormous number generally present. However, the goal of the DDDR is to provide an electron density profile for the HF absorption calculation. Thus, much of the detail of the ion chemistry is ignored, but enough remains to include all important source and loss processes to obtain a good electron density profile.

The AbbyNormal electron density profile and MSIS neutral atmosphere are used to calculate HF signal loss in decibels per kilometer (Figure 1). The loss per kilometer is the integrated for the vertical transit. The E region is included because approximately 10% of the non-deviative absorption occurs in the E region.

More Model Description Details

Model Input
Remote sensing SMEI data from CASS/USU (Space Environment Corp.)

Model Output

• Vertically integrated absorption values in decibels for 5, 10, and 15 MHz HF signals.
• Vertically integrated of Hall conductivity in mhos.
• Vertically integrated of Pedersen conductivity in mhos.

These outputs are two-dimensional global maps. These are provided for the whole day requested at 30 minute intervals. The format of each files provides the geo-latitude and geo-longitude node information with the global output values. The files can be read using FORTRAN code:

READ(1,’(8X,I6)’)NX
READ(1,’(1P,6E12.4)’)(GLON(I),I=1,NX)
READ(1,’(8X,I6)’)NY
READ(1,’(1P,6E12.4)’)(GLAT(J),J=1,NY)
READ(1,’(8X,2I6)’)NX,NY
READ(1,’(1P,6E12.4)’)((VALUE(I,J),I=1,NX),J=1,NY)

References and relevant publications
Eccles, J. V., R. D. Hunsucker, D. Rice, and J. J. Sojka, Space weather effects on midlatitude HF propagation paths: observations and a data-driven D-region model, Space Weat

CCMC Contact(s)
Masha Kuznetsova
301-286-9571

Developer Contact(s)
J. Vincent Eccles