Accession Number : AD0737355

Title :   An Operational Approach to Forecasting Polar Cap Absorption (PCA) Events.

Descriptive Note : Technical memo.,

Corporate Author : WEATHER WING (4TH) ENT AFB COLO

Personal Author(s) : Krause,George J.

Report Date : DEC 1971

Pagination or Media Count : 57

Abstract : One aspect of the Aerospace Environmental Support Center (AESC) support involves the effect of solar proton events upon transpolar high frequency (HF) radio propagation. This study addresses the problem of predicting the occurrence of Polar Cap Absorption (PCA) events resulting from solar proton enhancements near earth. Various aspects of the energetic solar flare event are reviewed and an attempt is made to assess their relative importance in arriving at a PCA forecast. Data pertinent to the flare event are considered in five general classes: radio burst data, X-ray burst data, optical data, solar region history, and the sector structure of the interplanetary magnetic field. An evaluation checklist is developed for use by the AESC forecaster. The checklist reflects the varying degrees of contributions of information in the five categories toward determining the 'Total PCA Factor.' (Author)

Descriptors :   (*IONOSPHERIC DISTURBANCES, PREDICTIONS), SOLAR FLARES, MAGNETIC STORMS, RADIOFREQUENCY INTERFERENCE, HIGH FREQUENCY, IONOSPHERIC PROPAGATION

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE