Manual detection of glacier extents on Kilimanjaro, Mount Kenya, and in the Rwenzori Range in 2021/2022

Tropical glaciers are helpful indicators of climatic changes in high-altitude environments. In East Africa, the glaciers in the three high-mountain regions Kilimanjaro, Mount Kenya and the Rwenzori Range have retreated substantially since the late 19th century. However, as there are no recent estimates for all regions, our study updates the time series of tropical glacier extent in East Africa. The methodological approach of the investigation is manual detection of ice body margins based on high-resolution satellite images of the PlanetScope program from 2021/2022. We performed three types of detection that included a minimum, a primary and a maximum extent, to indicate the range of the probable glacier area and account for individual allocation of pixels and influences of shaded or snow-covered areas.