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.

On the connection between variations o f atmospheric electricfield as measured at ground surface in the Central Antarctica and ionospheric potential Fig. 3. Diurnal course o f correlation coefficient (R) for 1998-2001 The average value of regression coefficient (a) = 0.66. It is less than in Bums et al. (2005), but we used the corrected values of the field, while in (Bums et al. 2005) were used the measured values without correction. For the case study we used the same reference level (ETH) and calculated <t>sw- Some examples are shown in fig.4. -Л- к '\ v- •- -7* . I Wr t Ц - 1 - *- 00.000300 0600 08. 00 12.00 15.00 16.00 2100 00.00 UTh S о 20 •s .y ■ 4- -V 0000 0300 0600 0900 1200 1500 16.002100 0000 UTh -Wl | March 22 2000 f UJ 10r -ft­ г 's [ A J 1 X К _ * ■ H ■* 'v* r** 00.000300 06.000900 1200 15: 001600 2100 0000 UTh 2 МГ s a V -- i %3 P 4 (v- zt 0 k f ►V4 L* . 0000 0300 06000900 1200 1500 1800 21000000 UTh Fig. 4. Examples of simultaneous records of variations of the solar wind imposed part of the surface electric field (Ezj) and the solar wind imposed potential variations of the ionosphere (W,), calculated by the Weimer model. We can see that the variations of the near-surface electric field are very close to the variations of the solar wind imposed ionospheric potential. Conclusions We have shown that the ionospheric electric fields can penetrate to the earth surface in the Polar Regions and their contribution to the atmospheric electric field can be more than 50 % o f the mean value. Linear regression analysis allows to divide the main sources o f variations of surface electric field and to allocate the thunderstorm part of atmospheric electric field. Diurnal variation o f thunderstorm part of near ground field coincides exactly with the famous Carnegie curve for the Antarctic summer (October-February). Variations of near-surface electric field are in good agreement with variations o f the solar wind imposed ionospheric potential calculated by the Weimer model both a statistically and for specific events. References Bums, G.B., et a l, 2005. Interannual consistency o f bi-monthly differences in diurnal variations of ground-level vertical electric field. J. Geophys. Res. 110, DIO, doi: 10.1029/2004JD005469. Chalmers 1967. Atmospheric Electricity. Pergamon Press, London, 515 p. Comey, R .C , et al. 2003. The influence of polar-cap convection on the geoelectric field at Vostok, Antarctica. J. Atmos. Solar-Terr. Phys. 65, 345. Frank-Kamenetsky et a l, 2001 Variations of the atmospheric electric field in the near­ pole region related to the interplanetary magnetic field. J. Geophys. Res. 106 (A l), 179. Hairston, M .R , Heelis, R .A , 1990. Model of the high-latitude ionospheric convection pattern during southward interplanetary magnetic field using DE 2 data. J. Geophys. Res. 95 (A3), 2333. Hays P .B , Roble, R .G , 1979. A quasi-static model of global atmospheric electricity 1 The lower atmosphere. J. Geophys. Res. 84, 3291. Jackson J.D. Classical Electrodynamics. New- York - London, 1962, 702 p Park, C.G., 1976. Downward mapping of high-latitude ionospheric electric fields to the ground. J. Geophys. Res. 81,168. Tinsley et al. 1998 South Pole electric field responses to overhead ionospheric convection, J. Geophys. Res. 103,26,137. Weimer, D.R. 2001, An improved model of ionospheric electric potentials including substorm perturbations and application to the GEM November 24, 1996 event, J. Geophys. R es, 106, p. 407, Atmosphere. Handbook, 1992 (in Russian). Weimer, D .R , 1995. Models of high-latitude electric potentials derived with a least error fit of spherical harmonic coefficients, J. Geophys. R es, 100, 19,595. 173