Physics of auroral phenomena : proceedings of the 33rd Annual seminar, Apatity, 02 - 05 March, 2010 / [ed.: A.G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2011. - 206 с. : ил.

M.A. Knyazeva, А.А. Namgaladze shifting the anomaly crests toward the geomagnetic equator starts at more earlier hours. As a result the equatorial trough is filled. The equatorial sides of the EEDR’s are moved to lower latitudes and their steepness is decreased. The analogous model calculations without taking into account the thermospheric wind induced field-aligned ion transport have shown (Fig. 2) that the EEDR’s have disappeared (top row o f the cuts) as well as the eastward electric field areas (bottom row of the maps) at middle and low latitudes. This confirms the role of the thermospheric wind in the forming of the EEDR’s and proves the dynamo origin o f these eastward electric field areas. Л ф = 20 kV Л ф = 60 kV £ a оT33 Lg(n rrr3) 1 ,1 °;65 .............. 11,0° G e om a g n e tic la titu d e (d e g .) Eastward electric field (mV/m) h=175km 18 19 20 21 22 23 0 1 2 3 M LT (hours) Figure 1. At the top r o w - the calculated by the UAM-MSIS with taking into account the thermospheric wind induced field-aligned ion transport the geomagnetic altitude-latitude distributions o f Lg(nJ along the night-time geomagnetic meridian 01:30 MLT for the altitude range from 800 to 3000 km, at the bottom row - the corresponding geomagnetic latitude-longitude distributions of the eastward electric field at the altitude 175 km for 24:00 UT 16.04.2002. At the left column - the meridional cut and map corresponding to the model calculation with A<p=20 kV, at the right column - with Л<р=60кВ. The pointers indicate to EEDR’s. Л ф = 20 kV Л ф = 60 kV E Ф X) Э U) о"D CD £0 £о CD CD Figure 2. The same ion transport. Lg(ne, n r 3) G e om a g n e tic latitu de (d e g .) Eastward electric field (mV/m) h=175 km 18 19 20 21 22 23 0 1 2 3 4 5 6 MLT (h ou rs) as in Fig. 1, but without taking into account the thermospheric wind induced field-aligned 118