Predictability of Dst index based upon solar wind conditions monitored inside 1 AU

The formula of Burton et al. [1975] provides a quick and simple means by which the strength of the ring current and the Dst index can be calculated based solely on upstream solar wind density, velocity, and the north/south component of the magnetic field. Solar wind data from ISEE 3, the Pioneer Venus Orbiter, and Helios A are used to show how well Dst predictions based on the Burton et al. formula match Dst observations for upstream monitors at various heliospheric distances. It is shown that a solar wind monitor that provides a substantial geomagnetic forecast lead time, with usable predictions of the characteristics of the solar wind, can be stationed -0.7 AU if it is near the ecliptic plane and within 10° east to 5° west of the Earth-Sun line. It is also shown that the Burton et al. formula predicts equally well the Dst index resulting from the passage of disturbed solar wind, associated with either interplanetary coronal mass ejections or stream-interaction regions. A solar sail-type spacecraft is proposed as the ideal monitor for forecasting purposes.

[1]  F. Neubauer,et al.  Statistical properties of fast magnetoacoustic shock waves in the solar wind between 0.3 Au and 1 Au: Helios-1,2 observations , 1985 .

[2]  V. Pizzo.  A three-dimensional model of co-rotating streams in the solar wind. 2: Hydrodynamic streams , 1979 .

[3]  R. Woo.  A synoptic study of doppler scintillation transients in the solar wind , 1988 .

[4]  C. Russell,et al.  Coronal mass ejection and stream interaction region characteristics and their potential geomagnetic effectiveness , 1995 .

[5]  L. Burlaga,et al.  Interplanetary magnetic clouds at 1 AU , 1982 .

[6]  C. Russell,et al.  An empirical relationship between interplanetary conditions and Dst , 1975 .

[7]  D. Baker,et al.  Bidirectional solar wind electron heat flux events , 1987 .

[8]  C. Russell,et al.  On the cause of geomagnetic storms , 1974 .

[9]  Daniel N. Baker,et al.  Magnetospheric Impulse Response for Many Levels of Geomagnetic Activity , 1985 .

[10]  G. Siscoe.  A unified treatment of magnetospheric dynamics with applications to magnetic storms , 1966 .

[11]  K. Marubashi,et al.  The Space Weather Forecast Program , 1989 .

[12]  D. Colburn,et al.  Interplanetary field and geomagnetic variations a unified view , 1969 .

[13]  J. Bartels.  Terrestrial-magnetic activity and its relations to solar phenomena , 1932 .

[14]  G. Gloeckler,et al.  Energetic proton and helium fluxes associated with interplanetary shocks and their relation to the solar wind composition , 1986 .

[15]  Wolfgang Baumjohann,et al.  The magnetopause for large magnetic shear: AMPTE/IRM observations , 1986 .

[16]  P. Gazis,et al.  Stream dynamics between 1 AU and 2 AU: A comparison of observations and theory , 1985 .

[17]  R. Schwenn.  Large-scale structure of the interplanetary medium , 1990 .

[18]  C. Russell,et al.  Proxy studies of energy transfer to the magnetosphere , 1991 .

[19]  M. Kivelson,et al.  Solar wind control of auroral zone geomagnetic activity , 1981 .

[20]  Edward J. Smith,et al.  Comparison of ISEE‐1 and ‐3 interplanetary magnetic field observations , 1980 .

[21]  S. Akasofu.  A source of the energy for geomagnetic storms and auroras. , 1964 .

[22]  Edward J. Smith,et al.  Factors controlling degree of correlation between ISEE 1 and ISEE 3 interplanetary magnetic field measurements , 1982 .

[23]  K. Marubashi.  Structure of the interplanetary magnetic clouds and their solar origins , 1986 .

[24]  C. Russell,et al.  Geomagnetic activity and the beta dependence of the dayside reconnection rate , 1994 .