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| Titel |
The efficiency of mechanisms driving Subauroral Polarization Streams (SAPS) |
| VerfasserIn |
H. Wang, H. Lühr |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 29, no. 7 ; Nr. 29, no. 7 (2011-07-20), S.1277-1286 |
| Datensatznummer |
250017062
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| Publikation (Nr.) |
 copernicus.org/angeo-29-1277-2011.pdf |
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| Zusammenfassung |
| We have investigated the seasonal and diurnal variation of SAPS
(Subauroral Polarization Streams) occurrence based on 3663 SAPS
events identified in DMSP ion drift observations in the Northern
Hemisphere during July 2001 and June 2003. Their relationships
with high latitude convection electric field, substorm, and
ionospheric conductivity have been addressed. SAPS occurrences
show a clear seasonal and diurnal variation with the occurrence
rates varying by a factor of 5. It is found that the convection
electric field might play a dominant role in association with SAPS occurrence. Peak
convection electric fields mark the occurrence maximum of SAPS.
Substorm might play a secondary role related to SAPS occurrence. It account for
the secondary maximum in SAPS occurrence rate during December
solstice. Our work demonstrates that the substorm induced electric
field can develop SAPS during relatively low global convection.
Somewhat low fluxtube-integrated conductivity is favorable for SAPS to
develop. Another topic is the temporal relationship between SAPS
and substorm phases. SAPS can occur at substorm onset, substorm
expansion and recovery phases.
Most probably SAPS tend to occur 60 min/45 min after
substorm onset during quiet/more
disturbed geomagnetic activity, respectively. This indicates that
enhanced global convection helps SAPS to develop quicker during
substorms. The peak plasma velocity of SAPS is increased on
average only by 5–10 % by the substorm
process. |
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