The dataset contains disdrometer data acquired at Sakurajima Volcano (Japan) by two Laser Precipitation Monitors (Thies Clima) from 5 to 20 November 2023. Data were obtained beneath volcanic plumes emitted by weak explosive activity at 3 different sites depending on wind direction (see LPM coordinates below). The campaign was conducted as part of an international collaboration between the Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) and the Laboratoire Magmas et Volcans (LMV), the University of Geneva (UNIGE), the University of Bremen (and the Sakurajima Volcano Observatory (SVO).

Files in this dataset follow the naming rule VolcanoName_LPMSiteNumber_ISODate.csv :
-SAKURAJIMA_LPM1_20231111_004059_081345UTC.csv
-SAKURAJIMA_LPM1_20231115_010552-045952UTC.csv
-SAKURAJIMA_LPM2_20231111_025416_081948UTC.csv
-SAKURAJIMA_LPM2_20231111_054500_055633UTC.csv
-SAKURAJIMA_LPM2_20231115_015801_020956UTC.csv
-SAKURAJIMA_LPM2_20231115_030937_031601UTC.csv
-SAKURAJIMA_LPM2_20231115_035428_042818UTC.csv
-SAKURAJIMA_LPM2_20231115_035938_040436UTC.csv
-SAKURAJIMA_LPM2_20231115_040439_040937UTC.csv
-SAKURAJIMA_LPM2_20231115_040938_041538UTC.csv
-SAKURAJIMA_LPM3_20231114_010451_011129UTC.csv
-SAKURAJIMA_LPM3_20231116_071056_082623UTC.csv

LPM coordinates:
Site #1: Long: 130.672293°; Lat: 31.559876°
Site #2: Long: 130.678855°; Lat: 31.555204°
Site #3: Long: 130.689436°; Lat: 31.619182°

LPM disdrometer data specifications:
All LPM data files are in .csv with semicolon separators. File names indicate the volcano, the LPM site number, the date (YYYYMMDD), the start and end time of the file (HHMMSS). Times are in UTC (Local Time -9 hours during the campaign). Data were obtained using a baud rate of 9600 (max number of ~25 detected particle per second) and the “drop by drop” mode of LPM that provides size and velocity of each detected particles. These are raw data with no additional post-treatment.
Column 1: ISO Date and time format YYYY-MM-DDTHH:MN:SS.sssZ
Column 2: ADC value (/)
Column 3: Event duration (10 µs)
Column 4: Time stamp (ms)  – Running duration since the disdrometer has been turned on.
Column 5: Particle size (mm)
Column 6: Fall velocity (m/s)
Column 7: “Hamburger” Particle size (mm) – to be used for rain particles
Column 8: “Hamburger” Fall velocity (m/s) – to be used for rain particles
Column 9: Device internal temperature (°C)

How to cite:
Freret-Lorgeril, V., Latchimy, T., Fries, A., Thivet, S., Guéhenneux, Y., Bonadonna, C., & Peyrin, F. (2026). The VOLcano DOppler RAdar and Disdrometers (VOLDORAD) observation service – Sakurajima 2023 campaign using Laser Precipitation Monitor (LPM) optical disdrometers [Dataset]. Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Laboratoire Magmas et Volcans (LMV), University of Geneva (UNIGE). https://doi.org/10.25519/VOLDORAD_SAKU_LPM23

-------------------------------------------------------------------

-Publication for LPM data from site #1: 
Freret-Lorgeril, V., Latchimy, T., Fries, A., Thivet, S., Mereu, L., Bonadonna, C., Diaz-Vecino, C., Lemus, J., Scollo, S., Poulidis, E., Delage, P. Cacault, Y. Guéhenneux, A., Aupert, S., Ghestem, M., Peyrin, F. Towards real-time quantification of tephra fallout during explosive volcanic eruptions using optical disdrometers. Earth. Planet. Sci. Lett. (in preparation)

-Publication for LPM data from sites #2 and #3:
Thivet, S., Simionato, A., Díaz-Vecino, C., Lemus, J., Freret-Lorgeril, V., Poulidis, A. P., Iguchi, M., Bonadonna, C. (2026). In-situ evidence of volcanic ash aggregation during fallout from combined ground- and UAS-based observations. Sci Rep 16, 15083. https://doi.org/10.1038/s41598-026-45460-x

-VOLDORAD DOI (in preparation)


