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| Titel |
Longitudinal differences of the PMSE strength at high Arctic latitudes |
| VerfasserIn |
Ralph Latteck, Werner Singer, Nimalan Swarnalingam, Jan Maik Wissing, Chris Meek, Allan H. Manson, James Drummond, Wayne K. Hocking |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250035519
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| Zusammenfassung |
| Observations of Polar Mesosphere Summer Echoes (PMSE) obtained by the ALWIN VHF
radar, located in Andenes, Norway (69-N, 16-E) and by the Resolute Bay VHF radar, located
in Nunavut, Canada (75-N, 95-W), are characterized by differences in occurrence rate and
PMSE strengths, with generally lower levels at Resolute Bay. Even though both radars are
well calibrated, the effect of the different radar hardware, especially the antenna systems, on
the observations still causes concerns if comparisons of results from both sites are
presented.
Now, PMSE observations with identical radar hardware and identical analysis software
are possible using the recently installed SKiYMET meteor radar at Eureka (80-N, 86-W) and
the SKiYMET meteor radar at Andenes. Eureka is located in the same longitudinal sector as
Resolute Bay, but 5 degrees north of the site, the Andenes SKiYMET radar is co-located with
the ALWIN VHF radar. Both SKiYMET radars are calibrated using cosmic sky noise
variations.
A 4-week measurement campaign was performed during July in 2008, with both the
Andenes and Eureka meteor radars running in a special mode designed for PMSE studies.
Lower levels of PMSE strength were found at Eureka, confirming the earlier observations at
Resolute Bay obtained by VHF radar. The observations are discussed in relation
to dynamics, thermal conditions, and ionization. Strong indications exist that the
observed differences of PMSE strength are related to the different levels of ionisation
due to precipitating particles in the auroral oval and inside the polar cap. Global
maps of precipitating energetic electrons (energy band: 6.5 keV–9.46 keV) and
energetic protons (energy band 80 keV–240 keV) derived from POES satellites clearly
indicate that Eureka and Resolute Bay are always inside the polar cap where, under
geomagnetically quiet conditions, ionisation due to particle precipitation is missing. |
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