Accession Number : ADP006295

Title :   Updated Climatological Model Predictions of Ionospheric and HF Propagation Parameters,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Reilly, M. H. ; Rhoades, F. J. ; Goodman, J. M. ; Hulburt, E. O.

Report Date : 03 MAY 1990

Pagination or Media Count : 9

Abstract : Several climatological models predict ionospheric parameters. A few also predict HF circuit parameters, such as the maximum usable frequency (MUF). Using conventional sunspot number inputs, we compare ICED, RADARC, and IONCAP model prediction performance for the F2 layer critical frequency foF2. Monthly median, 5-day average, and daily sunspot numbers, which are based on the 10.7 cm. solar flux, are used for this purpose, along with the ICED effective sunspot number. Relating prediction points to ionosonde data of comparable corrected geomagnetic latitude, in conjunction with an effective sunspot number, improves prediction accuracy. Near-real-time (NRT) updates of an ionospheric model from observations at a single station is found to dramatically improve predictions of foF2 out to distances of thousands of kilometers, as compared with the use of a global sunspot number. Similar performance for other ionospheric and HF circuit parameters is indicated. For the purpose of NRT predictions of the entire electron density profile the use of two distinct sunspot numbers for the bottomside, coupled with one or more parameters for the topside, is suggested for model updates from a single station.

Descriptors :   *IONOSPHERIC PROPAGATION, *CLIMATE, FORECASTING, IONOSPHERIC DISTURBANCES, HIGH FREQUENCY, SOLAR CYCLE, DIURNAL VARIATIONS, ELECTRON DENSITY.

Subject Categories : Radiofrequency Wave Propagation
      Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE