Long-Term Lidar Observations of Volcanic Ash from Sakurajima

抄録

Lidar observations of volcanic ash in Sakurajima, Japan, were conducted during 2016–2024 to determine the volcanic impact on the atmosphere. The range from the lidar observatory to the vent was divided into four zones, and the characteristics of the extinction coefficient were then analyzed. The discrimination threshold between cloud and volcanic ash was suggested, and volcanic activity reports by the Japan Meteorological Agency (JMA) were employed to explain the long-term variation of the extinction coefficient coupled with the high depolarization ratio measured by lidar. The correlation between the number of eruptions mentioned in the JMA report and the monthly mean extinction coefficient was low. This result suggests other smaller-scale eruptions affect atmospheric conditions around the volcano.