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dc.contributor.advisorKoustov, Alexander V.en_US
dc.creatorGhezelbash, Mohsenen_US
dc.date.accessioned2013-04-09T17:52:46Z
dc.date.available2013-04-09T17:52:46Z
dc.date.created2013-03en_US
dc.date.issued2013-04-09en_US
dc.date.submittedMarch 2013en_US
dc.identifier.urihttp://hdl.handle.net/10388/ETD-2013-03-949en_US
dc.description.abstractThis thesis has two major objectives. The first objective is to investigate the seasonal and diurnal variations in occurrence of HF coherent echoes. We assess F-region echo occurrence rates for the PolarDARN HF radars at Inuvik (INV) and Rankin Inlet (RKN) and the auroral zone SuperDARN radars at Saskatoon (SAS) and Prince George (PGR) for the period of 2007-2010. We show that the INV and RKN PolarDARN radars show comparable rates of echo occurrence all the time and they detect 1.5-2.5 times more echoes through ½-hop propagation mode (MLATs=80°-85°) than the SAS and PGR SuperDARN radars through 1½-hope propagation mode (MLATs=75°-80°). For all four radars, the winter occurrence rates are about ~2 times higher than the summer rates. For observations in the dusk, midnight and dawn sectors, equinoctial maxima are evident. The pattern of echo occurrence in terms of MLT/season is about the same for all radars with clear maxima near noon during winters and summers and enhanced (as compared to other time of the day) occurrence rates during equinoctial dusk and dawn hours. Additionally, to investigate the effect of solar cycle on occurrence of F-region echoes, we consider the near noon and near midnight echo occurrence rates for the Saskatoon radar over the period of 1994-2010. We show that there is a strong, by a factor of ~10, increase in SAS night-side echo occurrence towards solar maximum. The effect does not exist for the dayside echoes; moreover, a decrease in number of echoes, by a factor of ~2, was discovered for the declining phase of the solar cycle. The second objective is to evaluate the electron density and the electric field as factors controlling the occurrence of F-region echoes. We use observations of these two ionospheric parameters measured by CADI ionosonde and RKN observations of echo occurrence rates over Resolute Bay (MLAT=83°). We show that there is a correlation in changes of echo occurrence and electron density changes for 3 years of radar-ionosonde joint operation (2008-2010). The comparison of radar-ionosonde data shows that the enhanced echo occurrence at near noon hours during summer months correlate with the enhanced electric field during these periods.en_US
dc.language.isoengen_US
dc.subjectPolar/SuperDARN coherent radarsen_US
dc.subjectCHAIN CADI ionosondeen_US
dc.subjectEarth's ionosphereen_US
dc.subjectHF radio propagationen_US
dc.subjectIonospheric plasma irregularitiesen_US
dc.subjectF-region HF echoesen_US
dc.subjectElectric fielden_US
dc.subjectElectron densityen_US
dc.titleOccurrence and Causes of F-region Echoes for the Canadian PolarDARN/SuperDARN Radarsen_US
thesis.degree.departmentPhysics and Engineering Physicsen_US
thesis.degree.disciplinePhysicsen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Science (M.Sc.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US
dc.contributor.committeeMemberSofko, George J.en_US
dc.contributor.committeeMemberRangacharyulu, Charyen_US
dc.contributor.committeeMemberSalt, Eric J.en_US


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