Tracking of Volcanic Ash from Sakurajima Eruption by Image Analysis of Himawari-8

Sakurajima erupts frequently and brings a fall of ash in the neighboring area. It is important to know the plume containing volcanic ash is diluted and transported after the eruption. By applying image processing technologies, we have developed an algorism to capture plume of volcanic ash and their temporal evolution using satellite images of Himawari-8. Because the information of both cloud and the volcanic ashes was included in a satellite image, we picked candidate domain of volcanic ashes area by applying Random Forest. The temporal evolution of the plume was traced by combining the Random Forest and 3D labeling process to distinguish misrecognized areas. Some case studies demonstrated that our algorism could capture the plume of volcanic ashes more clearly in comparison with a conventional technique using Dust RGB, especially in the nighttime.