CUTLASS/IMAGE observations of high-latitude convection features during substorms

Details CUTLASS/IMAGE observations of high-latitude convection features during substorms CUTLASS/IMAGE observations of high-latitude convection features during substorms

Jun 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997angeo..15..692y&link_type=abstract

Annales Geophysicae, vol. 15, Issue 6, pp.692-702

Physics

18

Scientific paper

The CUTLASS Finland HF radar has been operational since February 1995. The radar frequently observes backscatter during the midnight sector from a latitude range 70-75° geographic, latitudes often associated with the polar cap. These intervals of backscatter occur during intervals of substorm activity, predominantly in periods of relatively quiet magnetospheric activity, with Kp during the interval under study being 2- and &Sgr;Kp for the day being only 8-. During August 1995 the radar ran in a high time resolution mode, allowing measurements of line-of-sight convection velocities along a single beam with a temporal resolution of 14 s, and measurement of a full spatial scan of line-of-sight convection velocities every four minutes. Data from such scans reveal the radar to be measuring return flow convection during the interval of substorm activity. For three intervals during the period under study, a reduction in the spatial extent of radar backscatter occurred. This is a consequence of D region HF absorption and its limited extent in the present study is probably a consequence of the high latitude of the substorm activity, with the electrojet centre lying between 67° and 71° geomagnetic latitude. The high time resolution beam of the radar additionally demonstrates that the convection is highly time dependent. Pulses of equatorward flow exceeding sim600 m s-1 are observed with a duration of sim5 min and a repetition period of sim8 min. Their spatial extent in the CUTLASS field of view was 400-500 km in longitude, and 300-400 km in latitude. Each pulse of enhanced equatorward flow was preceded by an interval of suppressed flow and enhanced ionospheric Hall conductance. The transient features are interpreted as being due to ionospheric current vortices associated with field aligned current pairs. The relationship between these observations and substorm phenomena in the magnetotail is discussed.

Affiliated with

Also associated with

No associations

Rating

CUTLASS/IMAGE observations of high-latitude convection features during substorms does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with CUTLASS/IMAGE observations of high-latitude convection features during substorms, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and CUTLASS/IMAGE observations of high-latitude convection features during substorms will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1472607