Monitoring ionospheric response to auroral electrojet activity from sub-auroral to equatorial latitudes in the East Asian-Australian longitudinal sector over a solar cycle (1978–1986)

摘要: Large auroral and ionospheric databases, covering a solar cycle (1978-1986), were used to obtain comprehensive evaluation of the electrojet effect (as inferred from AE-index) on response in both hemispheres sub-auroral equatorial latitudes. The study was limited East Asian-Australian longitudinal sector where data are available chain nine latitudinally displaced stations. Enhancement standard parameter, virtual height F-region (Delta h'F) recorded by vertical-incidence ionosondes. trace disturbance. Unlike previous studies this type, total magnetic data, hourly intervals, derive correlation coefficient r between two intrinsically different parameters: Delta h'F AE-index for local nighttime (20-06 LT or 10-20 UT). A suitable averaging smoothing technique applied enhance trend these parameters. It is evident that fluctuations ionosphere (for stations: Yakutsk Siberia Hobart Canberra Australia) closely resemble surges, over cycle. linear highly significant, being close 0.6 most time; during years maximum activity (1981-1983) approached 0.8. consistently high r, regardless season, applies only poleward station study, Yakutsk. stations (Hobart Canberra) positioned further equatorwards show strong decline summer but have winter equinoxes. There general towards lower latitudes, suggesting substorms whole diminishing with distance source equator. appears be an anomalous increase as observed around 10 degrees invariant latitude. These findings appear first long-term proof symmetry responses substorm northern southern ovals which important contribution space climatology. suggested aurorally generated acoustic gravity waves (AGWs), manifested global large scale travelling disturbances (LSTIDs), may contribute auroral-ionospheric phenomena. (C) 1999 Elsevier Science Ltd. All rights reserved.