A relationship between foE trends and geomagnetic activity long-term variations has been revealed for the first time. By analogy with earlier obtained results on the foF2 trends it is possible to speak about the geomagnetic control of the foE long-term trends as well. Periods of increasing geomagnetic activity correspond to negative foE trends, while these trends are positive for the decreasing...

The semiannual variation in geomagnetic activity is well established in geomagnetic data Its explanation has remained elusive, however. We propose, simply, that it is caused by a semiannual variation in the effective southward component of the interplanetary field. The southward field arises because the interplanetary field is ordered in the solar equatorial coordinate system, whereas the inter...

Geomagnetic field variation in support for indoor positioning and navigation has recently attracted considerable interest because of the advantage that technology based on the geomagnetic field has no infrastructure needs. Test using sensitive magnetometers has confirmed that it is possible to use geomagnetic field information for positioning purposes, however there are still issues to be addre...

According to NOAA space weather scales, geomagnetic storms of scales G5 (3-h index of geomagnetic activity Kp=9), G4 (Kp=8) and G3 (Kp=7) are dangerous for satellites, aircrafts, and even for technology on the ground (influence on power systems, on spacecraft operations, on HF radio-communications and others). We show on the basis of statistical data, that these geomagnetic storms, mostly accom...

Thermospheric neutral density derived from the GRACE A satellite and normalized at altitude of 490 km (?) are used to investigate ? behavior during period recurrent geomagnetic activity (25 January - 5 May, 2005) caused by solar wind high-speed streams (HSSs). The north south hemispheric values divided in three latitudinal bins analyzed separately dayside nightside. variations, not solar/geomag...

Active magnetic control is studied as a means to improve the capabilities and perfonnance of gravity gradient stabilized spacecraft. Active magnetic control eliminates the need for a passive damper and can reduce significantly the costs and complexity of other functional parts of the spacecraft. The system under study includes three magnetic torquers, one three-axis magnetometer, and a control ...

Observations performed by the Earth Observing System Microwave Limb Sounder instrument on board the Aura satellite from 2004 to 2009 (2004 to 2014) were used to investigate the 27 day solar rotational cycle in mesospheric OH (O3) and the physical connection to geomagnetic activity. Data analysis was focused on nighttime measurements at geomagnetic latitudes connected to the outer radiation belt...

[1] In this brief report, the interplay between meteorological and geomagnetic activity influences on the low-latitude ionosphere is studied. Specifically, the disruption of the dominant wave-4 longitudinal structure of the equatorial ionization anomaly (EIA) by geomagnetic storms is investigated in connection with a sequence of three coronal mass ejections in July 2004. Observations of in situ...