Potential Links between Precipitation and Anthrax Outbreak at North-West Siberia

West Siberia is a region subject to fast warming and unstable precipitation regime. In 2016, the most devastating anthrax outbreak in seventy years occurred in the northern part of the region. A working hypothesis suggests that permafrost thawing led to an exposure of old infected carcasses. We performed a thorough analysis of climatic factors in the region. Our analysis of soil temperature observations from the last 20 years indeed reveals rapid permafrost thawing near outbreak localization starting from 2010. We further analyzed meteorological observations to estimate the effect of warming and precipitation on permafrost. We showed that permafrost thawing was significantly accelerated during two consequent years with anomalously thick snow cover. Furthermore, spread of the disease was possibly intensified by an extremely dry summer. Precipitation in June-July 2016 did not exceed 10% of the climatological normals in the region. We conclude that epidemiological situation concerning anthrax remains highly unstable in the region due to the drastic decrease in summer precipitation and potential winter precipitation extremes.