Physics of auroral phenomena : proceedings of the 39th annual seminar, Apatity, 29 February-4 March, 2016 / [ed. board: N. V. Semenova, A. G. Yahnin]. - Апатиты : Издательство Кольского научного центра РАН, 2016. - 167 с. : ил., табл.

"Physics o f Auroral Phenomena". Proc. XXXIX Annual Sem inar, A patity, pp. 97-100. 2 0 1 6 © Polar Geophysical Institute, 2016 Polar Geophysical Institute DAYTIME NmF2 ANOMALOUS DEPENDENCE FROM SOLAR ACTIVITY IN THE MIDDLE AND SUBAURORAL LATITUDES IN JANUARY 2012-2015 M. K limenko7, N. K o renkova', V. L eshchenko', A. M arkov2, A. Abdullaev2, K.G. Ratovsky3, A. V esn in3 ' West D epartm ent o f Pushkov IZM IRAN RAS, 41, P o b ed yA v ., Kaliningrad, 236017, Russia ‘Imm anuel Kant Baltic Federal University, Kaliningrad, Russia 3Institute o f Solar-Terrestrial P hysics SB RAS, Irkutsk, Russia e-mail: maksim .klimenko@mail.ru Abstract. This paper presents the investigation results of the dependence of the January daytime ionospheric F2 layer peak electron density ( NmF2 ) from solar activity (<F,0.7>27) for 2012-2015. The ground-based ionosonde data depict following paradox: the daytime NmF2 values in January of 2014 were less than those in January of 2015, whereas </гю.7>27 values in 2014 were greater than in those 2015. Constructing linear regressions for different data sets and analyzing the geomagnetic activity behavior we made a preliminary conclusion about a positive impact of geomagnetic activity on the January daytime NmF2 values. Introduction The F2 layer peak electron density (NmF2) is larger for higher solar activity and is proportional to sunspots number and the F l01 index (Bryunelli and Namgaladze, 1988). Solar activity dependence of ionospheric F region parameters diurnal and seasonal variations in the East-Siberian region is investigated in details by Ratovsky et al. (2015). It was shown, that the higher solar activity leads to the growth rate of the NmF2, which is greatest in the afternoon at winter solstice. Contrary, NmF2 weakly depends on solar activity in the nighttime winter ionosphere which is caused by plasma flows from a plasmasphere. Lei et al. (2005) concluded that N,„F2 above Millstone Hill at 12:00 LT in winter increases linearly with increasing in solar activity proxy Fm index. Hence, linear function can be used to represent the N,„F2 and proxy F 107 correlation. In this paper we examined N,„F2 dependence on the solar activity in January 2012-2015 at different locations. Observation data We analyzed the daily F 107 index data from the web-site http://lasp.Colorado.edu/lisird/tss/noaa_radioJlux.htm l and geomagnetic activity index Ap from the web-site http://wdc.kugi.kyoto-u.ac.jp/kp/index.html fo r January- February 2012-2015. We obtained 27-day and 81-day averaged values of solar (<F|0.7> 2 7 and<F| 0 . 7 > 8 i) and geomagnetic (<Ap>21 and <Ap>% i) activity indices for 19 January of each year (Table 1). <Ap>n and <Ap> g) showed that the considered periods were geomagnetically quiet. We used <FWJ> 27 to examine NmF2 dependence on the solar activity. We used <Fm >n since it was similar to < /rio.7>8i f°r the considered periods (see Table 1). In order to estimate NmF2 diurnal variation in the middle and subauroral latitudes dependence on solar activity we used the ionosonde data of seven stations from the Space Physics Interactive Data Resource(SPIDR) ( http://spidr.ngdc.noaa.gov ) . We carried out the manual processing of SPIDR data due to various technical aspects of data recording. In addition we used the NmF2 observation data from the Irkutsk and Kaliningrad ionosondes. The latter were obtained from the manually scaled ionograms using interactive ionogram scaling software, SAO Explorer [Reinisch et al., 2004; Khmyrov et al., 2008] in the case of the Irkutsk ionosonde and PARUS software [Karpenko and Manaenkova , 1996] in the case of the Kaliningrad ionosonde. The geographic coordinates of all considered stations are presented in the Table 2. We obtained 27-daily Station Latitude, degrees Longitude, degrees Port Stanley -51.7 -57.8 Jeju 33.5 126.5 I-Cheon 37.1 127.5 Boulder 40.0 -105.3 Rome 41.8 12.5 Pruhonice 50.0 14.6 Irkutsk 52.5 104.0 Kaliningrad 54.0 20.0 Moscow 55.5 37.3 Table 2. The list of stations Year <F10.7>27 <F10.7>8! <Ap>27 <Ap>gi 2012 128 124 7.3 6.5 2013 122 110 5.4 4.7 2014 149 154 4.7 6.8 2015 132 139 9.3 10.2 Table 1. 27 and 81 averaged values of the F10.7 and Ap indexes for 19 January 2012 - 2015 97