Physics
Scientific paper
Aug 1999
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999jgr...10417217s&link_type=abstract
Journal of Geophysical Research, Volume 104, Issue A8, p. 17217-17232
Physics
5
Ionosphere
Scientific paper
Auroral roar, a narrowband (δf/f<0.1) emission near 2 and 3 times the ionospheric electron gyrofrequency (2fce and 3fce), is observed with a meridional chain of LF/MF/HF radio receivers located in northern Canada spanning 67° to 79° invariant latitude. Observations of these emissions are compared with the auroral electrojet location inferred from the Canadian Auroral Network for the OPEN Program Unified Study (CANOPUS) magnetometer array. Variations in the intensity of the observed auroral roar emissions and in the invariant latitude of the most intense emissions are correlated with movements of the poleward boundary of the electrojet. For example, substorm onsets, which appear as rapid poleward expansions of this boundary, result in screening of the emissions from the underlying ground stations because of precipitation-induced ionization in the lower ionosphere. In four of the five study days the peak emission intensity is located 0°-9° poleward of the poleward electrojet boundary inferred from the magnetometers. In one case the peak emission intensity is up to 10° equatorward of the poleward electrojet boundary. In all cases, there is a tendency for the latitude of the most intense auroral roar emissions to track the movements of the electrojet location inferred from the magnetometer data. For two examples, the footprint of the Fast Auroral Snapshot (FAST) satellite passes within 3° of one or more of the ground stations, and the satellite detects unstable electron populations in the polewardmost auroral arc, reinforcing the scenario that auroral roar emissions are generated by these electrons in the polewardmost arc and propagate into the polar cap where conditions are often favorable for their detection at ground level.
Carlson Carl W.
LaBelle James
Rostoker Gordon
Shepherd Simon G.
No associations
LandOfFree
Latitudinal dynamics of auroral roar emissions 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 Latitudinal dynamics of auroral roar emissions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Latitudinal dynamics of auroral roar emissions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1268800