Item request has been placed!
×
Item request cannot be made.
×
Processing Request
Infrasound - the cause of strong Polar Mesosphere Winter Echoes?
Item request has been placed!
×
Item request cannot be made.
×
Processing Request
- المؤلفون: Swedish Institute of Space Physics ;Swedish Institute of Space Physics ; School of Meteorology ; School of Meteorology ; EISCAT Scientific Association ; EISCAT Scientific Association ; Leibniz Institute of Atmospheric Physics ; Leibniz Institute of Atmospheric Physics ; Kirkwood, S.; Chilson, P.; Belova, E.; Dalin, P.; Häggström, I.; Rietveld, M.; Singer, W.
- المصدر:
Annales Geophysicae; Annales Geophysicae, European Geosciences Union (EGU), 2006, 24 (2), pp.475-491
- نوع التسجيلة:
Electronic Resource
- معلومة اضافية
- Publisher Information:
HAL CCSD European Geosciences Union (EGU)
- نبذة مختصرة :
International audience
The ESRAD 52-MHz and the EISCAT 224-MHz radars in northern Scandinavia observed thin layers of strongly enhanced radar echoes from the mesosphere (Polar Mesosphere Winter Echoes - PMWE) during a solar proton event in November 2004. Using the interferometric capabilities of ESRAD it was found that the scatterers responsible for PMWE show very high horizontal travel speeds, up to 500 ms-1 or more, and high aspect sensitivity, with echo arrival angles spread over as little as 0.3°. ESRAD also detected, on some occasions, discrete scattering regions moving across the field of view with periodicities of a few seconds. The very narrow, vertically directed beam of the more powerful EISCAT radar allowed measurements of the spectral widths of the radar echoes both inside the PMWE and from the background plasma above and below the PMWE. Spectral widths inside the PMWE were found to be indistinguishable from those from the background plasma. We propose that scatter from highly-damped ion-acoustic waves generated by partial reflection of infrasonic waves provides a reasonable explanation of the characteristics of the very strong PMWE reported here.
- الموضوع:
- Note:
Annales Geophysicae
English
- Other Numbers:
RNQ oai:HAL:hal-00317954v1
hal-00317954
893026228
- Contributing Source:
CENTRE NAT DE LA RECHERCHE SCIENTIFIQUE
From OAIster®, provided by the OCLC Cooperative.
- الرقم المعرف:
edsoai.ocn893026228
HoldingsOnline
No Comments.