Multiradar Observations of the Polar Tongue of Ionization
Abstract
We present a global view of large-scale ionospheric disturbances during the main phase of a major geomagnetic storm. We find that the low-latitude auroral, and polar latitude regions are coupled by processes that redistribute thermal plasma throughout the system. For the large geomagnetic storm on 20 Nov 2003, we examine data from the high-latitude incoherent scatter radars at Millstone Hill, Sondrestrom, and EISCAT Tromso, with SuperDARN HF radar observations of the high-latitude convection pattern and DMSP observations of in-situ plasma parameters in the topside ionosphere. We combine these with north polar maps of storm time plumes of enhanced total electron content (TEC) derived from a network of GPS receivers. The polar tongue of ionization (TOI) is seen to be a continuous stream of dense cold plasma entrained in the global convection pattern. The day side source of the TOI is the plume of storm enhanced density (SED) transported from low latitudes in the post-noon sector by the sub-auroral disturbance electric field. Convection carries this material through the day side cusp and across the polar cap to the night side where the auroral F region is significantly enhanced by the SED material. The three incoherent scatter radars provided full altitude profiles of plasma density, temperatures, and vertical velocity as the TOI plume crossed their different positions, under the cusp, in the center of the polar cap, and at the midnight oval/polar cap boundary.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 03, 2005
- Accession Number
- ADA443897
Entities
People
- A. Van Eyken
- Anthea J. Coster
- F. J. Rich
- J. M. Holt
- John C. Foster
- M. Mccready
- Philip J. Erickson
- R. A. Greenwald
- R. J. Barnes
- W. Rideout