The Spatiotemporal Characteristics of Urban Snow Disasters in Xinjiang over the Last 60 Years

Abstract

Based on the daily observations from 83 meteorological stations in Xinjiang between 1961 and 2020, urban snow disasters were divided into four grades: extremely severe, severe, medium and light. The patterns in the spatiotemporal variability of snow disasters and the relationship between snow disasters and the Northern Hemisphere circulation indices are discussed. The results show that snow disasters were more frequent in the north than in the south, and severe and extremely severe snow disasters mainly occurred in the north. Over the past 60 years, the frequency of medium and above snow disasters has been increasing significantly, while the frequency of light disasters has been decreasing significantly. The areas with significant changes are mainly located in the snow-rich area of Northern Xinjiang. The above changes were more evident during 1991–2020 and occurred in more than 70% of the whole area. Compared to the previous 30 years, the annual average, the maximum and minimum frequency of snow disasters classified as medium and above increased. This is especially true for severe and extremely severe disasters, which increased by more than 70%. Severe and extremely severe snow disasters in the north are significantly and positively correlated with the Northern Hemisphere Polar Vortex Central Intensity Index (NHPVCI), the India-Burma Trough Intensity Index (IBTI) and negatively correlated with AO during the cold season and the winter. Severe snow disasters in the south are positively correlated with the IBTI during winter and autumn.