This demonstrates that gravity wave-induced variations during SSWs constitute a significant source of high latitude thermospheric variability.
Bisikalo et al. (1995) proposed energetic O+ ions precipitation to be a possible source of high-latitude Oh concentration, and hence the boundary conditions must be based on Oh temperature and density values found in the experimental data and literature.
Ground and satellite observations (Popecki et al. 1993; Anderson et al. 1996) have suggested that ions of the plasma sheet, drifting from the nightside to dayside, can develop a temperature anisotropy capable of generating EMIC waves; therefore, equatorially generated EMIC waves can represent the source of high-latitude waves.
After reflection at the western boundary, it takes only a quarter of a cycle (i.e., T ∗/4) for equatorial KWs to travel eastward to the eastern boundary of the model domain (see blue lines in Fig. 5 a), where some disturbances are deflected poleward along the eastern boundary to be the source of mid-latitude RWs which then propagate westward (Fig. 5 b).
It is also worth noting here that, depending on ground conductivities, slow GICs can also be the most effective source of GICs at low magnetic latitudes, for example, in Hokkaido, Japan (Watari et al. 2009; Pulkkinen et al. 2010).
As widely known, the dominant source of induction in the mid-latitudes is a symmetric ring current in the magnetosphere, described spatially by the spherical harmonic Y 1 0 = cos θ and temporally by the corresponding coefficient ε 1 0. The latter can approximately be related to the Dst index as (Olsen and Kuvshinov [2004]) ε 1 0 ≈ − Dst 1 + Q ~, (11).
Survey cluster locations were geo-coded by using combinations of global positioning systems, electronic gazetteers (Google Earth, Encarta, and Alexandria), and other sources of longitude and latitude.
After all survey data were assembled, each surveyed community was geo-coded using combinations of global positioning systems, electronic gazetteers (Google Earth, Encarta and Alexandria) and other sources of longitude and latitude such as a settlement database collated by FAO-SWALIM.
These dynamos are the primary sources of the low-latitude electric field, but high-latitude processes also contribute and are discussed as well.
Since (18a) is seamlessly solvable at all latitudes with φ app∗=0 at coastlines, the source of the westward energy flux of mid-latitude RWs in the model output has been successfully illustrated in the present study.
