13:45 〜 14:00
[PEM12-11] Statistical study on spatial distribution of plasma waves observed by PWE/OFA
キーワード：あらせ、プラズマ波動、内部磁気圏
In the present paper, we investigated the spatial distribution of the power spectrum measured by the PWE/OFA (Plasma Wave Experiment/Onboard Frequency Analyzer) on board the Arase.
The OFA (onboard frequency analyzer) measures electric and magnetic wave spectra in the frequency range below 20 kHz continuously with a time resolution of 1 second as a nominal operation mode. This frequency range is crucial for plasma wave observation because chorus waves, magnetospheric hiss, lightning whistlers and magnetosonic waves are detected.
First, we compared our results with the previous statistical work done using the spectral data recorded by the Van Allen Probes (e.g. Malaspina et al., 2017), and confirmed that the results are almost consistent with those derived from the observation by Van Allen Probes at low latitudes. Next we examined the spatial distribution of the wave activities in the off-equatorial region. Because the inclination of the Arase is 31 degrees, which is much larger than that of Van Allen Probes (~10 degrees), this orbital configuration provides the ability to explore not only the equatorial region but also the off-equatorial region in the inner magnetosphere.
In the presentation, we report the global distributions of various plasma waves as a function of magnetic latitude, magnetic local time and L-value.
The OFA (onboard frequency analyzer) measures electric and magnetic wave spectra in the frequency range below 20 kHz continuously with a time resolution of 1 second as a nominal operation mode. This frequency range is crucial for plasma wave observation because chorus waves, magnetospheric hiss, lightning whistlers and magnetosonic waves are detected.
First, we compared our results with the previous statistical work done using the spectral data recorded by the Van Allen Probes (e.g. Malaspina et al., 2017), and confirmed that the results are almost consistent with those derived from the observation by Van Allen Probes at low latitudes. Next we examined the spatial distribution of the wave activities in the off-equatorial region. Because the inclination of the Arase is 31 degrees, which is much larger than that of Van Allen Probes (~10 degrees), this orbital configuration provides the ability to explore not only the equatorial region but also the off-equatorial region in the inner magnetosphere.
In the presentation, we report the global distributions of various plasma waves as a function of magnetic latitude, magnetic local time and L-value.