Accession Number:

ADA200761

Title:

Ionospheric Scintillations and In-Situ Measurements at an Auroral Location in the European Sector

Descriptive Note:

Corporate Author:

EMMANUEL COLL BOSTON MA

Report Date:

1988-10-04

Pagination or Media Count:

15.0

Abstract:

The orbiting HiLat satellite offered a unique opportunity for studying the ionospheric scintillation parameters in relation to the in-situ measurements of ionization density, drift velocity, field-aligned current, and particle precipitation during the sunspot minimum period. This paper discusses the results of such a morphological study based on observations at the auroral oval station of Tromso, Norway. The dynamics of the spatial and temporal extent of this region are illustrated in the invariant latitudemagnetic local time grid. The geometrical enhancement of scintillations observed during the alignment of the propagation path with the local magnetic L-shell is shown to be the most consistent and conspicuous feature of scintillations in the nighttime auroral oval. The steepening of phase spectral slope in this region is indicative of the presence of L-shell aligned sheet-like irregularities at long scale lengths. The seasonal variational of total electron content TEC determined from the differential Doppler measurements of HiLat transmissions is discussed in relation to the in-situ density measurements at 830 km. The results are also utilized to illustrate the dependence of ionospheric structure parameters on short-term variability of solar activity during the sunspot minimum period. Special effort is made to illustrate that the joint study of scintillationTEC and in-situ parameters provides an insight into the nature of magnetospheric coupling with the high latitude ionosphere. Keywords Amplitude and phase scintillations Total electron content In-situ density Auroral oval Sunspot cycle variation Irregularity anisotropy Reprints.

Subject Categories:

  • Atmospheric Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE