The Physical Foundation of Forecasting Disturbances in the Geospace From Solar Disk Characteristics

The five main types of antisunward propagating energetic fluxes (particles and emission) may be thought of as well established to date, the effects of which lead to a particilar character of disturbance in the near-terrestrial environment (the Earth's magnetosphere, ionosphere and atmosphere). The strongest global restructuring of the magnetosphere and ionosphere is caused by fluxes of relatively dense n of 1-70 cm-3 at the Earth's orbit) Solar Wind (SW) quasi-neutral, low-energy (E ＜ 10 keV) plasma which cause magnetospheric and ionospheric storms lasting 24 hours or longer. For that reason, main attention is given to their study at the initial stage of research. The physical essence of the method of predicting disturbances in the near-terrestrial space environment, the amplitude of which can be expressed in, for example, the Kp index units, involves:(1) identifying all the most geo-effective SW streams of type, (2) determing their sources on the solar disk,and (3) quantifying the correlations between the characteristics of their solar sources with a maximum value of the Kp-index that is caused by the concerned type of SW stream. Semi-phenomenological relations have been obtained, which relate parameters of type SW stream sources to characteristics of geomagnetic storms:storm commencement, the time at which the storm intensity reaches its maximum values, the storm duration,as well as to the storm amplitude expressed in terms of geomagnetic indeces.      

Prediction of Magnetospheric Disturbances Caused by a Quasi-Stationary Solar Wind

When predicting parameters of quasi-stationary Solar Wind (SW) streams at 1 AU, it is customary to use, as the indicator of solar sources, the Bases of Open Magnetic Tubes (BOMT) on the solar surface obtained via a calculation relying on a new Bd-technique of harmonic expansion of the magnetic field from daily full-disk magnetograms developed by Rudenko[4]. By considering an example of 17 events, it is shown that the correspondence between fast SW streams at the Earth's orbit and the BOMT, calculated with ≤ 24 h time resolution, makes up about 94%, while the correspondence of SW stereams with the CH in the light of the 10830 A line is about 29%. With this technique, the predictability of maxima of the Kp index of magnetospheric disturbance caused by a fast quasi-stationary SW, is over 90%, and the prediction accuracy of the maximun velocity vm of the stream is ±15%.