Space-time structure of the morning aurora inferred from coincident DMSP-F6, -F8, and Sondrestrom incoherent scatter radar observations

Technical Report · Fri Oct 01 04:00:00 EDT 1993

OSTI ID:5094728

Watermann, J; De La Beaujardiere, O; Spence, H E

On rare occasions, observations from the DMSP-F6 and -F8 spacecraft and the Sondrestrom incoherent scatter radar coincide in space. Such coincidence offers a unique opportunity to study temporal vs spatial variations on a small scale. The authors discuss data from one of those occasions, with observations made in the dawn sector in the presence of moderate auroral precipitation during a magnetically quiet period. The DMSP satellites measured vertical electron and ion flux and cross-track plasma drift while the radar measured the ionospheric electron density distribution and line-of-sight plasma velocities. The authors combine these data sets to construct a two-dimensional map of a possible auroral pattern above Sondrestrom. It is characterized by the following properties. No difference is seen between the gross precipitation patterns measured along the DMSP-F6 and -F8 trajectories (separated by 32 km in magnetic east-west direction and some 4 s in travel time in magnetic north-south direction), except that they are not exactly aligned with the L shells. However, F6 and F8 observed minor differences in the small-scale structures. More significant differences are found between small-scale features in the DMSP precipitation measurements and in radar observations of the E region plasma density distribution. These measurements are separated by 74 km, equivalent to 2.4 deg, in magnetic longitude, and 0-40 s in time along the spacecraft trajectories (varying with magnetic latitude). Large-scale magnetospheric-ionospheric surfaces such as plasma flow reversal, poleward boundary of the keV ion and electron precipitation, and poleward boundary of E-region ionization, coincide.

• Research Organization: Aerospace Corp., El Segundo, CA (United States). Technology Operations
• OSTI ID: 5094728
• Report Number(s): AD-A-275442/2/XAB; TR--92(2940)-4; CNN: F04701-88-C-0089
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
CHARGED-PARTICLE TRANSPORT
E REGION
EARTH ATMOSPHERE
ELECTRON DENSITY
IONOSPHERE
PLANETARY IONOSPHERES
PLASMA DENSITY
PLASMA DRIFT
RADIATION TRANSPORT