10:15 AM - 10:30 AM
[MTT39-06] Infrasonic waves from Martian dust devils seen in atmospheric pressure fluctuations
★Invited Papers
Dust devils are vertical vortexes along with dust, which can be several kilometers in diameter, and are one of the most iconic atmospheric phenomena on Mars.
On the other hand, observations by the barometer PS onboard the Mars InSight spacecraft have confirmed the existence of internal gravity waves and infrasonic waves on Mars by Don Banfield et al(2020).
Therefore, considering the spatio-temporal scale of dust devils, there is a possibility that low-infrasonic waves and internal gravity waves are excited from the dust devils and detected by the barometer. If infrasonic waves and internal gravity waves originating from the dust devils are detected by the barometer, dust devils located far from the spacecraft can be counted and their characteristics can be statistically determined. In this study, we attempt to detect infrasonic sound waves and internal gravity waves that may have originated from dust devils from the data of the barometer PS onboard InSight.
Since those waves excited by the dust devils may reach the spacecraft before the dust devils themselves, the power spectrum was obtained from the atmospheric pressure data for 30 minutes before the dust devils were detected by PS, referring to the dust devils list compiled by Onodera et al. (2023). Furthermore, the power spectrum ratio was obtained from the power spectrum and its moving . Among the total of 12569 dust devils reported by Onodera et al. (2023), 15 of them had a central pressure drops larger than 6 Pa. The amplitudes of infrasonic and internal gravity waves excited by these dust devils are expected to be relatively large. We focused on the power spectrum ratios for these 15 dust devils in this study,
and calculated the running mean of each power spectrum ratio in the direction of frequency. The average in the running means among the 15 cases suggested that there may be significant signals around 0.4 Hz and 0.7 Hz.
On the other hand, observations by the barometer PS onboard the Mars InSight spacecraft have confirmed the existence of internal gravity waves and infrasonic waves on Mars by Don Banfield et al(2020).
Therefore, considering the spatio-temporal scale of dust devils, there is a possibility that low-infrasonic waves and internal gravity waves are excited from the dust devils and detected by the barometer. If infrasonic waves and internal gravity waves originating from the dust devils are detected by the barometer, dust devils located far from the spacecraft can be counted and their characteristics can be statistically determined. In this study, we attempt to detect infrasonic sound waves and internal gravity waves that may have originated from dust devils from the data of the barometer PS onboard InSight.
Since those waves excited by the dust devils may reach the spacecraft before the dust devils themselves, the power spectrum was obtained from the atmospheric pressure data for 30 minutes before the dust devils were detected by PS, referring to the dust devils list compiled by Onodera et al. (2023). Furthermore, the power spectrum ratio was obtained from the power spectrum and its moving . Among the total of 12569 dust devils reported by Onodera et al. (2023), 15 of them had a central pressure drops larger than 6 Pa. The amplitudes of infrasonic and internal gravity waves excited by these dust devils are expected to be relatively large. We focused on the power spectrum ratios for these 15 dust devils in this study,
and calculated the running mean of each power spectrum ratio in the direction of frequency. The average in the running means among the 15 cases suggested that there may be significant signals around 0.4 Hz and 0.7 Hz.