[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...

Several applications exist for transiting liquid droplets through the near-Earth space environment. Numerical results are presented for the charging of liquid droplets of trimethyl pentaphenyl siloxane (DC705) in three different plasma environments: ionosphere, auroral, and geosynchronous Earth orbit (GEO). Nominal and high geomagnetic activity cases are investigated. In general, high levels of...

Solar activity is the dynamic energy source behind all solar phenomena driving space weather. During an active solar period, violent eruptions occur more often on the Sun. The solar flares (SFs) and coronal mass ejections (CMEs) shoot energetic and highly charged particles towards Earth that ensuing ionospheric and geomagnetic disturbances. The some geomagnetic disturbances illuminate night ski...

Oscillatory modes with the period of approximately 7–8 years were detected in monthly time series of sunspot numbers, geomagnetic activity aa index, NAO index and near-surface air temperature from several mid-latitude European locations. Instantaneous phases of the modes underwent synchronization analysis and their statistically significant phase coherence, beginning from 1950’s, has been obser...

Assessment of the actual geomagnetic activity level from local magnetometer monitoring is of importance in earth sciences and exploration but also for different kinds of risk assessment with regard to electronics and electric power facilities. Wavelet based signal processing methods are applied to extract meaningful information from magnetic field time series in a noisy environment. Using a pro...

We present a new composite of geomagnetic activity which is designed to be as homogeneous in its construction as possible. This is done by only combining data that, by virtue of the locations of the source observatories used, have similar responses to solar wind and IMF (interplanetary magnetic field) variations. This will enable us (in Part 2, Lockwood et al., 2013a) to use the new index to re...

Intense late-cycle solar activity during October and November 2003 produced two strong geomagnetic storms: 28 October–5 November 2003 (October) and 19– 23 November 2003 (November); both reached intense geomagnetic activity levels, Kp=9, and Kp=8+, respectively. The October 2003 geomagnetic storm was stronger, but the effects on the Earth’s ionosphere in the mid-latitude European sector were mor...

The K index was devised by Bartels et al. (1939) to provide an objective monitoring of irregular geomagnetic activity. The K index was then routinely used to monitor the magnetic activity at permanent magnetic observatories as well as at temporary stations. The increasing number of digital and sometimes unmanned observatories and the creation of INTERMAGNET put the question of computer producti...

From the daily index Ap of geomagnetic activity, sequences of consecutive occurrence of Ap≤4 for four days and Ap≤7 for 8 days are identified in the period 1963-1998. A superposed epoch analysis is performed with the onset of these sequences and with eight different solar wind and IMF parameters. A systematic pattern of change from days preceding to the days following the quiet intervals is cle...

Numerical modelling of thermospheric temperature changes associated with periods of high geomagnetic activity are often inaccurate due to unrealistic representation of nitric oxide (NO) densities and associated 5.3-μm radiative cooling. In previous modelling studies, simplistic parameterisations of NO density and variability have often been implemented in order to constrain thermospheric temper...