Abstract
We report the first incoherent scatter radar observations-made at Arecibo Observatory-of remarkable bottom-side (<280 km) F-region sheet-like plasma structures with horizontal/vertical-scales of∼<1 km. These structures are an apparent manifestation of spread-F, appear to give rise to VHF coherent (FAI) scattering, and are clearly electrodynamic in origin involving a form of the Perkins spread-F instability process in the presence of relatively large E-fields and horizontal plasma gradients. The net instability process appears to be associated with downwelling features characteristic of the nighttime F-region. These structures-that may be self-similar on scales of ∼1-100 km-indicate considerable electrodynamic activity in the mid-latitude F-region on scales that have profound space-weather implications especially regarding deep scintillations on earth-space communications links.
Original language | English (US) |
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Pages (from-to) | 4167-4170 |
Number of pages | 4 |
Journal | Geophysical Research Letters |
Volume | 28 |
Issue number | 22 |
DOIs | |
State | Published - Nov 15 2001 |
All Science Journal Classification (ASJC) codes
- Geophysics
- General Earth and Planetary Sciences