National Aeronautics and Space Administration

Living With A Star

Targeted Research and Technology

The geoeffectiveness of solar cycle 23 as inferred from a physics-based storm model

ROSES ID: NRA-02-OSS-01      Selection Year: 2003      

Program Element: Independent Investigation: LWS

Principal Investigator: Vania Jordanova

Affiliation(s): University of New Hampshire

Project Member(s):
Torbert, Roy B COI University of New Hampshire
Farrugia, Charles John COI University of New Hampshire
Thorne, Richard Collaborator University of California Los Angeles


The energization of the ring current and its subsequent decay is the central aspect of geomagnetic activity. However, what mechanisms are responsible for energizing particles and for causing their loss, and how the relative importance of these mechanisms depends on the field and flow parameters in the near-Earth interplanetary (IP) medium as it varies over the solar cycle, are issues not well understood. In this proposal we aim at investigating these issues for solar cycle 23 using the continuous coverage of IP parameters provided by NASA's ACE and Wind satellites. By selecting a representative variety of temporal profiles of IP parameters during geomagnetic storms of Dst<-80 nT (i.e., moderate to major storms), we shall determine how the following phenomena known to be important in generating strong ring currents, are related to solar cycle phase: a) the spatial and temporal variability of the convection electric field; b) enhanced ionospheric outflows and nightside plasma sheet densities; c) saturation of the polar cap potential with the interplanetary electric field, and d) the strength of the ring current as a reflection of the changing activity in this solar cycle. For this task we shall employ our physics-based numerical code driven by models of the convection electric field tailored to the temporal profiles of IP parameters. A particular focus of this effort will be to extend our model to address the behavior of electrons of both non-relativistic and relativistic energies during storms, and the IP drivers/internal mechanisms which determine this behavior. The proposed work furthers the objectives of NASA's Living with a Star (LWS) program by a) addressing the energy flow through the solar wind - magnetosphere - ionosphere system during stormtime, since we include an electric field based on IP parameters, b) seeking to forecast strong ring currents through an investigation encompassing the whole range of solar activity seen in this cycle, and c) providing information on radiation belt electron dynamics, which can be used to reduce hazards to humans and technological systems during storms.


Performance YearReferenceInvestigation TypeActions
1Jordanova,Vania UNH - The geoeffectiveness of solar cycle 23...
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1Farrugia, C. J.; Matsui, H.; Kucharek, H.; Jordanova,...
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Performance YearReferenceActions
1Farrugia, C.; Matsui, H.; Kucharek, H.; Jordanova, V....

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