The Southern Hemisphere and equatorial region ionization response for a 22 September 1999 severe magnetic storm

Abstract. The ionospheric storm evolution process was monitored during the 22 September 1999 magnetic storm over the Australian eastern region, through measurements of the ionospheric Total Electron Content (TEC) from seven Global Positioning Systems (GPS) stations. The spatial and temporal variations of the ionosphere were analysed as a time series of TEC maps. Results of our analysis show that the main ionospheric effect of the storm under consideration are: the long lasting negative storm effect during a magnetic storm at mid-latitude regions; the strong, positive disturbances during the storm's main phase at auroral latitude regions; the effects of storm-induced equatorward directed wind causing a positive disturbance at high and mid-latitude stations with appropriate time shift between higher and lower latitudes; daytime poleward movement of depleted plasma that causes temporary suppression of the equatorial anomaly during the start of the storm recovery phase; and prompt penetration of eastward electric fields to ionospheric altitudes and the production of nearly simultaneous TEC enhancement at all latitudes. In general, we found dominant negative disturbance over mid and high latitudes and positive disturbance at low latitudes. A comparison of storm-time behaviour of TEC determined from GPS satellites, and foF2 derived from ionosondes at a range of latitudes, showed reasonable agreement between the two independent measurements.

[1]  Xiaoqing Pi,et al.  GPS normalization and preliminary modeling results of total electron content during a midlatitude space weather event , 2001 .

[2]  G. W. Prölss,et al.  Heating and radiation production by neutralized ring current particles , 1993 .

[3]  S. Basu,et al.  Ionospheric effects of major magnetic storms during the International Space Weather Period of September and October 1999: GPS observations, VHF/UHF scintillations, and in situ density structures at middle and equatorial latitudes , 2001 .

[4]  S. Ma,et al.  Combined ESR and EISCAT observations of the dayside polar cap and auroral oval during the May 15, 1997 storm , 2000 .

[5]  N. Balan,et al.  Relationship between nighttime total electron content enhancements and VHF scintillations at the equator , 1984 .

[6]  G.,et al.  Ionospheric Storm Effects at Subauroral Latitudes : A Case Study , 2022 .

[7]  H. Rishbeth,et al.  Geomagnetic storms in the Antarctic F-region. I. Diurnal and seasonal patterns for main phase effects , 1987 .

[8]  S. Schlüter,et al.  Total electron content of the ionosphere during thegeomagnetic storm on 10 January 1997 , 1999 .

[9]  A. D. Danilov.  F2-region response to geomagnetic disturbances , 2001 .

[10]  E. Sardón,et al.  Relationships between GPS-signal propagation errors and EISCAT observations , 1996 .

[11]  J. Lastovicka,et al.  Eects of geomagnetic storms on the ionosphere and atmosphere , 2001 .

[12]  Bela G. Fejer,et al.  Low latitude storm time ionospheric electrodynamics , 2002 .

[13]  G. J. Bailey,et al.  Solar and magnetic activity effects on the latitudinal variations of nighttime TEC enhancement , 1991 .

[14]  Norbert Jakowski,et al.  Geomagnetic Storm Effects on the Topside Ionosphere and Plasmasphere: A Compact Tutorial and New Results , 2000 .

[15]  B. M. Reddy,et al.  A comparative study of global ionospheric responses to intense magnetic storm conditions , 1998 .

[16]  J. Titheridge.  The electron content of the southern mid-latitude ionosphere, 1965-1971. , 1973 .

[17]  H. Rishbeth,et al.  Geomagnetic storms in the Antarctic F-region. II. Physical interpretation , 1989 .

[18]  E. Essex,et al.  Vertical E × B drift velocity variations and associated low-latitude ionospheric irregularities investigated with the TOPEX and GPS satellite data , 2003 .

[19]  A. Tan.  On the nighttime increase of NmF2 at Jicamarca on 2–3 February 1965 , 1982 .

[20]  E. Essex,et al.  Ionospheric total electron content and slab thickness determined in Australia , 1997 .

[21]  T. Fuller‐Rowell,et al.  How Does the Thermosphere and Ionosphere React to a Geomagnetic Storm , 2013 .

[22]  M. Buonsanto.  Ionospheric Storms — A Review , 1999 .

[23]  E. Essex,et al.  The southern-hemisphere mid-latitude day-time and night-time trough at low-sunspot numbers , 2003 .