11:45 AM - 12:00 PM
[PEM16-05] Comparison of pulsating aurora with and without internal modulation: simultaneous observations with ARASE
Keywords:Pulsating aurora, Chorus waves
During the first coordinated campaign observations of PsA with the ARASE/ERG satellite in March 2017, we obtained two good case examples of simultaneous observations of PsA and chorus by the all-sky imagers (ASIs) and ARASE. During one of the cases in Scandinavia on March 29 (Case A), the correspondence between the periodicities of chorus burst and main pulsation was extremely good. However, it was difficult to identify signatures of discrete chorus elements and internal modulation. During the other case in Alaska on March 30 (Case B), on the other hand, good correlation was seen between chorus elements and internal modulations. These results imply a relationship between the existence of discrete chorus elements and appearance of internal modulation. In the presentation, we discuss what kind of background conditions control the appearance of chorus elements and internal modulation by comparing the two case examples.
Acknowledgement: The operation of the EMCCD camera at Sodankylä has been supported by Sodankylä Geophysical Observatory (SGO).