[M-TT39] Brand-new scope of coupling geophysics being established by infrasound and associated waves

[MTT39-07] A Trial of high-density, high-sensitivity, and high-frequency micro-pressure observation in the main part of Fukuoka City

*Kensuke Nakajima¹, Masa-yuki Yamamoto², Yasuhiro Nishikawa², Midori Yamazaki², Yoshihiro Kakinami³, Mitsutaka Yasuda³, Megumi Sugimoto⁴, Hironobu Takahashi⁵, Momoko Kojima⁵, Daichi Takahara⁵, Koto Hirano⁵ (1.Department of Earth and Planetary Sciences,Flculty of Sciences,Kyushu University, 2.Department of System Engineering, Kochi University of Technology, 3.Hokkaido Information University, 4.Graduate School of Human Sciences, Osaka University, 5.National Institute of Advanced Industrial Science and Technology )

Keywords:infrasound, cumulonimbus, atmospheric gravity waves, high density meteorological observation, IoT, citizen science

1. Introduction
With recent technological advances, we can construct a compact (about 20 cm square), low-cost (several thousand yen per unit), biased but stable barometer with a measurement interval of 35 ms and sensitivity of 0.5 Pa by combining a capacitive MEMS sensor and a microcontroller (e.g. Imada and Nakajima [1]). Based on this, we have created a number of micro-pressure measurement packages with a view to their application to disaster prevention as a NICT-commissioned research project adopted in FY2022 [2], and have conducted observation experiments on a progressively larger scale, including small-scale observations in Kami City, Kochi Prefecture, and medium-scale observations in Ebetsu City, Hokkaido. In this presentation, we will describe the observation network currently deployed in the main part of Fukuoka City and preliminary observation results.

2. Observation Network and Instruments
Since August 2024, we have deployed A4 size observation equipment (sensor: Infineon DPS310) at 45 locations in and around the main part of Fukuoka City with the cooperation of Fukuoka City community centers, related facilities, private companies, and universities. Vaisala PTU300 was placed at three locations to confirm stability (see figure). Measurements (at 50 ms intervals, in 0.1 Pa increments) are transmitted to Kyushu University via a mobile router. Fukuoka City provided generous cooperation in the installation of the equipment at the community center [3]. Observations are scheduled to continue until August 2025.

3. Preliminary Results of Observation
At the meeting of JpGU, we will present some examples of atmospheric pressure fluctuations captured by the observation network, with video clips if possible. The planned examples include: (1) pressure fluctuations observed during a thunderstorm on September 16, 2024, although the network is still being deployed; (2) pressure fluctuations induced by seismic motions from the Hyuga Nada earthquake in August 2024 and January 2025; and (3) pressure fluctuations observed prior to the February 2, 2025 “Abiki” event.

References
[1] E. Imada and K. Nakajima, “Development of a micro-pressure observation system for observing atmospheric lamb waves excited by ground motion,” MTT45-P04, Japan Geoscience Union 2022 Meeting.
[2] National Institute of Information and Communications Technology, Commissioned Research on Advanced Telecommunications and Broadcasting Research 22605, “Demonstration-type research and development for solving social and regional issues by promoting digitalization such as data utilization: Standardization of a multi-point micro-pressure variation measurement package for regional disaster prevention and citizen-collaborated demonstration experiment in urban suburban and mountainous areas” https://www.nict.go.jp/collabo/commission/k_22605.html
[3] Fukuoka City Full Support Project for Demonstration Experiment, FY2024 adopted project “Multi-point measurement of infrastructure sound for regional disaster prevention” https://www.city.fukuoka.lg.jp/keizai/kigyo-renkei/mirai/fullsup/saitaitiran /R6_fullsupport_pj.html