Physics of auroral phenomena : proceedings of the 36th Annual seminar, Apatity, 26 February – 01 March, 2013 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2013. - 215 с. : ил., табл.

Magnetic reconnection site in the magnetotail during different solar wind streams Relationship between the latitude of the poleward edge of the auroral bulge and the distance of the reconnection site from the Earth For all 19 selected cases we determined the latitude o f the poleward edge of the auroral bulge at Geotail footprints meridian at the moment when Geotail registered a fast flow reversal in the magnetotail. Then we related this latitude with Geotail position in the magnetotail. The results are shown in Fig. 2, where the distance between Geotail and the Earth is evaluated by Geotail X-coordinate in earth radii. On the right panel cases observed during MCs are shown by diamonds, cases during RS - by crosses, those observed during Sheath - by circles, and cases during CIRs - by squares. On the left panel cases are grouped according their origin: cases connected with MCs and Sheaths are shown by diamonds, cases of RS and CIRs - by crosses. /X/, Re /X/, Re Fig. 2. Latitude o f the poleward edge o f the aurora (seen by Polar UV1 at the meridian o f Geotail) as a function o f the distance between Geotail and Earth at the moment of the flow reversal registration. From Fig.2 it is clearly seen that the reconnection site during substorms associated with recurrent solar wind streams is observed on the average at larger distances from earth |X|=25.7±2.8 RE than during substorms associated with magnetic clouds, the latter being at 15.±1.5 RE. Discussion and conclusion In this work we discuss the problem o f the magnetic reconnection site location in the magnetotail during substorms associated with different solar wind streams. It is shown that magnetic reconnection in the magnetotail takes place closer to Earth when substorm is observed during MC, and further in the tail (X coordinate in RE) for substorms during solar wind recurrent streams (RS). In this way our results conform to the results of Nagai et al., 2005. However by one-point data it is difficult to separate space and time variations. We plan to continue the investigations on reconnection site location for substorms driven by different solar wind structures using CLUSTER and THEMIS data. Acknowledgements. The paper was supported by the RFBR Grants 12-05-01030 and Program No 22 of the Presidium of the Russian Academy of Sciences (RAS) “Fundamental problems of the Solar system exploration”. The work was also partially supported by grant DID 02/8 from the Bulgarian National Science Fund. The study is a part of the joint Russian - Bulgarian Project “The influence of solar activity and solar wind streams on the magnetospheric disturbances, particle precipitations and auroral emissions” of PGI RAS and IKIT-BAS under the Fundamental Space Research Program between RAS and BAS. 11