Accession Number : ADA324453

Title :   Ionospheric Structure Specification and Systems Effects.

Descriptive Note : Final rept. 28 Nov 89-27 Nov 96,

Corporate Author : BOSTON COLL CHESTNUT HILL MA INST FOR SCIENTIFIC RESEARCH

Personal Author(s) : Hagan, M. P. ; Valladares, Cesar E.

PDF Url : ADA324453

Report Date : 15 JAN 1997

Pagination or Media Count : 293

Abstract : This is a comprehensive study of the sources of scintillation that disrupts world wide Air Force systems dependent on trans-ionospheric radiowave propagation. Measurement of the complete electrodynamics of sun aligned polar cap arcs has determined that the electromagnetic energy can be larger than the particle energy and can be an important contributor to the polar cap energy budget. An analysis of 1400 images from Qaanaaq, Greenland implies that the motion of polar cap arcs is controlled by the entry of open field lines into the polar cap. Based on a few substorm cases, polar cap arcs can persist for up to 90 min after Bz becomes southward. Experimental evidence and numerical simulation (GTIM) have shown that a patch formation event was associated with a large plasma jet. The level of plasma lines associated with auroral arcs can increase due to the action of bump on tail instability. We have deployed 6 RACAL and 2 GPS receivers at the equatorial station at Ancon, developed software to perform online and offline processing of the received scintillation signals, and determined for the first time the climatology of the zonal drifts of the irregularities that produce equatorial scintillation.

Descriptors :   *IONOSPHERIC SCINTILLATION, *POLAR CAP, *PLASMA WAVES, COMPUTER PROGRAMS, MATHEMATICAL MODELS, EQUATORIAL REGIONS, OCEAN CURRENTS, ELECTROMAGNETIC WAVE PROPAGATION, CONTINENTAL DRIFT, ANISOTROPY, GLOBAL POSITIONING SYSTEM, AURORAE, PLASMA JETS, ELECTRODYNAMICS, GREENLAND, IONOSPHERIC PROPAGATION, MAGNETOSTATICS, POLAR CAP ABSORPTION.

Subject Categories : Geology, Geochemistry and Mineralogy
      Radiofrequency Wave Propagation
      Atmospheric Physics
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE