POLAR GEOMAGNETIC DISTURBANCES

摘要: Results of recent observations geomagnetic disturbances in both northern and southern high latitudes are critically reviewed, various theories on these phenomena introduced. In Section 1, an additional daily variation, observed the polar areas magnetically quiet days, is discussed. The quiet-day variation regions consists Sq0-field which extension Sq-field established middle low field, Sqp, confined to cap areas. equivalent ionospheric electric current pattern Sqp-field two vortices, clockwise morning side counterclockwise afternoon cap, when viewed from above, their conjugate cap. intensity local summer about three times as large that winter. This seasonal change can be attributed conductivity ionosphere. interpreted being caused by transferring, through lines force, effect circular convections low-energy magnetospheric plasma driven solar wind. In 2, morphology part sudden commencement magnetic storms (SSC) described. SSC field universal increase due compression cavity storm wind DS(SSC), represented a transient enhancement Sqp-field. A preliminary reverse impulse takes place only It seems likely characteristics te interpreted, unified representation, those initial phase elliptically polarized hydromagnetic wave transports compressing stage cavity. In 3, auroral electrojets discussed basis they sporadic intermittent phenomena. Opinions interpretation electrojet divided. Chamberlain-Kern theory ascribing polarization precipitating proton-electron beams gradient, most plausible. certain must enhanced highly con- ductive zones. In 4, inter-relationship among (ΔH), luminosity (J) ionization (n) ionosphere relations expressed J ∝ n2 (ΔH)2 hold especially well zones. Electron 10 keV average energy accompanied protons seem probable agency result relations. In 5, results observational studies relationship for bays giant pulsations summarized. stations defined with respect unperturbed field. Similarity simultaneity at good. activated individual several degrees latitude 10–30 longitude developed stage. conjugacy holds between conjugately Geomagnetic minutes period hundred gammas amplitude also have very good conjugacy. They transverse waves generated magnetosphere transmitted along force towards Earth. vectors rotate counter-clockwise side, looking direction force. having larger ones smaller amplitude, may identified anisotropic isotropic modes respectively waves. In 6, so-called spiral patterns number upper atmospheric disturbance been proposed. locus blackout real Stormer orbit proton impact others some closed curve oval shape ascribed projection radiation belt particles (either electrons or protons) trapped distorted upon ionosphere. Section 7 deals gaps existing knowledge disturbances.