the daily record of geomagnetic variations at any world location typically shows a multitude of irregular changes in the field that represent the superposition of many spectral components whose amplitudes generally increase with increasing period. it has been a long established fact that variations in ground magnetic records are caused by the dynamo action in the upper atmosphere. these daily v...

Sea Floor ElectroMagnetic Stations (SFEMSs) are now operating at two deep seafloor sites called the 'WPB' and the 'NWP' in the West Philippine Basin and the Northwest Pacific Basin, respectively. One of the main objectives of the SFEMSs is to detect the geomagnetic secular variations on the deep seafloor where long-term geomagnetic observations have not so far been achieved. SFEMSs can measure ...

The cross-polar potential drop 8pc and the lowlatitude asymmetric geomagnetic disturbance field, as indicated by the mid-latitude ASY-H magnetic index, are used to study the average magnetospheric response to the solar wind forcing for southward interplanetary magnetic field conditions. The state of the solar wind is monitored by the ACE spacecraft and the ionospheric convection is measured by ...

We use incoherent scatter radar measurements from Millstone Hill and Saint Santin to study the midlatitude F region electrodynamic plasma drifts during geomagnetically quiet and active periods. We present initially a local time, season, and solar flux dependent analytical model of the quiet time zonal and meridional ExB drifts over these stations. We discuss, for the first time, the Saint Santi...

Data from the Jicamarca digisonde and the ROCSAT-1 satellite are employed to study the equatorial ionosphere on the west side of South America during April 1999–March 2000 for the concurrent bottomside spread F (BSSF) and plasma bubble events. This study, using digisonde and ROCSAT-1 concurrently, is the first attempt to investigate the equatorial spread F. Results show that BSSF and plasma bub...

We present a study of statistical relationships between the G condition, F1-layer and NmF2 negative disturbance occurrence probabilities and geomagnetic and solar activity indices Kp and F10.7, season, and geomagnetic latitude, using experimental data acquired by the Ionospheric Digital Database of the National Geophysical Data Center, Boulder, Colorado from 1957 to 1990. It is shown that the d...

An attempt has been made to study the influence of geomagnetic storm on the tropospheric acoustic gravity waves at equatorial station, Tirunelveli (8.7°N, 77.8°E), India. The daily average of the amplitude and phase of acoustic gravity waves has been studied for the period 2000-2004. Severe geomagnetic storms occurred during April and September 2000, April 2001, October and November 2003 and No...

In this paper, a geomagnetic matching navigation method that utilizes the geomagnetic vector is developed, which can greatly improve the matching probability and positioning precision, even when the geomagnetic entropy information in the matching region is small or the geomagnetic contour line's variety is obscure. The vector iterative closest contour point (VICCP) algorithm that is proposed he...