Assessing the Altitude and Dispersion of Volcanic Plumes Using MISR Multi-angle Imaging from Space: Sixteen Years of Volcanic Activity in the Kamchatka Peninsula, Russia

Volcanic eruptions represent a significant source of atmospheric aerosols and can display local, regional and global effects, impacting earth systems and human populations. In order to assess the relative impacts of these events, accurate plume injection altitude measurements are needed. In this work, volcanic plumes generated from seven Kamchatka Peninsula volcanoes (Shiveluch, Kliuchevskoi, Bezymianny, Tolbachik, Kizimen, Karymsky and Zhupanovsky), were identified using over 16 years of Multi-angle Imaging SpectroRadimeter (MISR) measurements. Eighty-eight volcanic plumes were observed by MISR, capturing 3-25% of reported events at individual volcanoes. Retrievals were most successful where high intensity events persisted over a period of weeks to months. Compared with existing ground and airborne observations, and alternative satellite-based reports compiled by the Global Volcanism Program (GVP), MISR plume height retrievals showed general consistency; the comparison reports appear to be skewed towards the region of highest concentration observed in MISR-constrained vertical plume extent. The report observations display less discrepancy with MISR toward the end of the analysis period, with improvements in the suborbital data likely the result of the deployment of new instrumentation. Conversely, the general consistency of MISR plume heights with conventionally reported observations supports the use of MISR in the ongoing assessment of volcanic activity globally, especially where other types of volcanic plume observations are unavailable. Differences between the northern (Shiveluch, Kliuchevskoi, Bezymianny and Tolbachik) and southern (Kizimen, Karymsky and Zhupanovsky) volcanoes broadly correspond to the Central Kamchatka Depression (CKD) and Eastern Volcanic Front (EVF), respectively, geological sub-regions of Kamchatka distinguished by varying magma composition. For example, by comparison with reanalysis-model simulations of local meteorological conditions, CKD plumes generally were less constrained by mid-tropospheric (< 6 km) layers of vertical stability above the boundary layer, suggesting that these eruptions were more energetic than those in the EVF