NFLUENCE OF RATE AND DENSITY OF RECURRENT SOLAR WIND FLOWS AND GEOMAGNETIC ACTIVITY INDICES (KP AND DST) ON THE STRUCTURE OF ELECTRON FLOWS GENERATED IN THE EARTHS OUTER RADIATION BELT AT GEOSTATIONARY ORBIT
The dynamic variations of electron flows reflect a complex balance between competitive acceleration mechanisms and losses of particles, the efficiency of which is determined both by solar wind parameters, and by parameters of magnetosphere defining the geomagnetic activity (i.e. by geomagnetic indices, Kp and Dst in particular). The article is devoted to a study of correlation between the dynamics of electron flows with variation of solar wind parameters and Kp- and Dst-indices. The article considers 29 cases of electron flow enhancement in the Earths outer radiation belt variations generated in 2007 under the influence of high-rate recurrent solar wind flows. The data received from the LANL-GEO satellite and the OMNI database has been used for parameters of solar wind and geomagnetic activity (Kp- and Dst-indices). The article contains analysis and quantitative assessment of the influence of solar wind rate V and density N variations and Kp- and Dst-indices of geomagnetic activity on the intensity of maximum electron flows of 31.7 keV (source electrons), 270 keV (‘embryonic’ electrons) and 925 keV (relativistic electrons). The ranges of parameters variation are as follows: solar wind rate is from 400 to 670 km/s; solar wind density is from 6 to 20 cm-3; Кр-index is from 15 to 30 units; |Dst| index is from 3 to 32 nT. The following five pairs of parameters were selected for analysis: rate V and Kp-index, rate V and Dst-index, rate V and density N, density N and Kp-index, density N and Dst-index. The variation of electron flow intensity is analyzed for each selected pair, with variation of one parameter and constant value of the other. The article shows the correlation between intensity variation and variation of relation between the absolute values of the selected parameters. The results are provided in the form of numerical values. In particular, during the analysis of variations of 31.7 keV and 925 keV electron flows, when rate V is increased at constant density N (increase of intensity of ~ 80% for 31.7 keV and of ~ 260% for 925 keV, for N = 14 cm-3) the electron flux variations are considerably greater than the flow variations at the increase of density with constant rate (reduction of ~ 30% for 31.7 keV and of ~ 45% for 925 keV, for V = 540 km/s). When rate V and Dst-index increase, the electron fluxes of 31.7 keV and 925 keV electrons are enhanced, also. The variations of fluxes at the increase of Dst-index at constant rate are approximately twice as much as the variations of flows at the increase of rate with constant values of Dst-index. The analysis has shown close similarity (functional, but not numeric) in the dynamics of 31.7 keV electrons (source electrons) and relativistic electrons at variation of solar wind rate and density and geomagnetic indices, however, intensity variations are greater for all 925 keV electron parameter relations. 270 keV electron flows enhance when density is increased, and reach the maximum value of~ 2,9∙103 el∙cm2∙s∙ster at N of ~ 12 - 18 cm-3, and after that when density is increased, this value remains unchanged (within the limits of 10%) and does not depend on variation of solar wind (400 - 640 km/s), Кр index (15 - 30 units) and |Dst|-index (3 - 20 nT). In fact, it demonstrates the fact that ‘embryonic’ electrons flow is mainly enhanced in the area of the source.