Pulsating auroras observed by a 30-Hz all-sky imager during the THEMIS-ground campaign on January 2008

We had an auroral observation campaign at Gillam (56.4N, 265.4E) and Fort Smith (60.0N, 248.1E), Canada on January 2-15, 2008, using white-light all-sky imagers (ASIs) (180 degree field of view (FOV)) with a sampling rate of 30 Hz. At ~0840 UT on 8 January, an auroral arc appeared from west in the FOV of ASI at Gillam. After an expansion of the aurora, active pulsating aurora was observed over the FOV of ASI during ~0850-0905 UT. After 0905 UT, weak pulsations lasted until 1000 UT at Gillam. During this pulsating aurora event, footprints of the THEMIS-D and -E satellites were located in the FOV of ASI at Gillam. These satellites observed intense bidirectional field-aligned electron fluxes with energies of ~1-30 keV during 0840-0905 UT at ~11 Re in the plasma sheet. Simultaneously, enhanced low frequency waves (below 100 Hz) were observed by these satellites. On the other hand, enhanced electron fluxes at higher energies (10-100 keV) and intense waves at ~1 kHz were also successively observed during ~0850-1000 UT. Similar THEMIS-ground conjunction events were obtained on 12-14 January at Gillam, during which the ASI observed active pulsating auroras. In this presentation, we show ground and satellite observations during these pulsating auroras and discuss possible formation processes of pulsating auroras in the plasma sheet.