Bibliography

Towards a National Space Weather Predictive Capability

Fox, Nicola; Ryschkewitsch, Michael; Merkin, Viacheslav; Stephens, Grant; Gjerloev, Jesper; Barnes, Robin; Anderson, Brian; Paxton, Larry; Ukhorskiy, Aleksandr; Kelly, Michael; , others;

Published by:       Published on:

YEAR: 2015     DOI:

Interplanetary magnetic field By control of prompt total electron content increases during superstorms

Large magnitude increases in ionospheric total electron content (TEC) that occur over 1\textendash3\ h on the dayside are a significant manifestation of the main phases of superstorms. For the largest superstorms of solar cycle 23 (based on the Dst index), ground networks of GPS receivers measured peak total electron content increases greater than a factor of 2 relative to quiet time TEC averaged over the broad latitude band \textpm40\textdegree for local times 1200\textendash1600\ LT. Near 30\textdegree latitude, the Halloween storms of October 29\textendash30, 2003 appeared to produce storm-time TEC exceeding quiet time values by a factor of 5 within 2\textendash3\ h of storm onset, at 1300\ LT. The physical cause of these large positive phase ionospheric storms is usually attributed to prompt penetration electric fields (PPEFs) initiated by Region 1 current closure through the ionosphere ( Nopper and Carovillano, 1978 mechanism). An unresolved question is what determines variation of the TEC response for different superstorms. It has been suggested that the cross polar cap potential and Region 1 currents are significant factors in determining PPEF in the equatorial ionosphere, which are related to the solar wind reconnection electric field estimated by Kan\textendashLee and others. In this paper, we show evidence that suggests B_y may be a significant factor controlling the TEC response during the main phase of superstorms. We analyzed the interplanetary conditions during the period that TEC was increasing for eight superstorms. We find that increasing daytime TEC during superstorms only occurs for large reconnection electric fields when B_y magnitude is less than B_z. The data suggest that B_z is a far more important factor in the TEC response than the reconnection electric field. We also find that TEC decreases following its peak storm-time value for two superstorms, even though B_z remains large and B_y magnitudes are less than B_z. Such decreases during the geomagnetic disturbance may indicate the role of magnetospheric shielding currents, or of changes in the thermosphere that have developed over the prolonged period of large solar wind electric field. Further analysis is warranted covering a wider range of storm intensities on the role of B_y in affecting the daytime TEC response for a range of storm intensities.

Mannucci, A.J.; Crowley, G.; Tsurutani, B.T.; Verkhoglyadova, O.P.; Komjathy, A.; Stephens, P.;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 08/2014

YEAR: 2014     DOI: 10.1016/j.jastp.2014.01.001

Geomagnetic storms; Ionosphere

Visualizing the fully three-dimensional plasmaspheric and ring current distribution from global EUV and ENA imaging

Zimmerman, MI; Hsieh, SW; Brandt, PC; Vandegriff, JD; Stephens, GK; Toigo, AD; Keika, K; Kusterer, MB; DeMajistre, R;

Published by:       Published on:

YEAR: 2013     DOI:

Estimating The Forces That Drive Ionosphere And Thermosphere Variability: Continuous Data And Assimilative Modeling

onosphere-thermosphere science has long been hampered by a lack of measurements of the underlying forces that determine plasma structure. These forces include electric fields, thermospheric composition, winds and solar EUV irradiance. All of these forces are dynamic quantities and of great importance to the underlying science. The rapid proliferation of electron density and total electron content measurements from ground and space-borne GPS receivers and other instruments suggests a great potential in the following indirect approach to estimating these forces: developing a model-based approach to retrieving the forces from the electron density structure and dynamics. The research community has just begun to explore such an approach, which addresses significant science questions previously out of reach.

Mannucci, Anthony; Pi, Xiaoqing; Butala, Mark; Stephens, Phil; Wilson, Brian; Komjathy, Attila; Iijima, Byron; Akopian, Vardan; Dumett, Miguel;

Published by: To advocate developing a model-based approach to retrieving the driving forces from measurements of electron density structure and dynamics      Published on:

YEAR: 2010     DOI: