DNA project 609 rada: auroral backscatter measurements. Final report, 31 Jan 1974--30 Sep 1975

Technical Report · Sun Feb 01 04:00:00 EST 1976

OSTI ID:7115891

Tsunoda, R T; Presnell, R I; Wang, T N.C.

This report summarizes the research results obtained from auroral backscatter studies using the DNA 609 radar system located at Homer, Alaska. The primary purpose of the backscatter studies was to improve understanding of the auroral-clutter-producing mechanism. Most of the results are based on coordinated experiments utilizing the 398-MHz phased-array radar at Homer, the SRI/DNA incoherent-scatter radar at Chatanika, and other complementary auroral measurement techniques. It was found that the problem can be most effectively approached by seeking both microscale and macroscale relationships, i.e., the relationships of local plasma parameters within the radar scattering volume producing auroral clutter, and the relationships of the large-scale auroral and magnetospheric conditions to the spatial distribution of auroral clutter, respectively. The results include the following: (1) Diffuse auroral clutter is apparently not produced by primary plasma waves generated by the Buneman--Farley two-stream instability. (2) The mechanism does not, however, appear to be unlike the quasilinear gradient-drift instability model proposed by Sudan et al. (1973), which can be driven by the primary two-stream waves. (3) There is a threshold electric field strength of 30 mV/m associated with the occurrence of 398-HMz diffuse auroral clutter. (4) The diffuse auroral clutter is closely associated with the auroral electrojets. (5) The evening diffuse auroral clutter is closely associated with downward field-aligned currents. (6) Discrete auroral clutter is closely associated with the discrete visual aurora. (GRA)

• Research Organization: Stanford Research Inst., Menlo Park, CA (USA)
• OSTI ID: 7115891
• Report Number(s): AD-A-031103
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALASKA
AURORAE
BACKSCATTERING
CURRENTS
DISTURBANCES
DRIFT INSTABILITY
EARTH ATMOSPHERE
ELECTRIC CURRENTS
ELECTROJETS
FREQUENCY RANGE
INSTABILITY
IONOSPHERE
MEASURING INSTRUMENTS
MHZ RANGE
MHZ RANGE 100-1000
NORTH AMERICA
PACIFIC NORTHWEST REGION
PLANETARY IONSPHERES
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
PLASMA WAVES
RADAR
RANGE FINDERS
SCATTERING
TWO-STREAM INSTABILITY
USA