Spatial and temporal variations of snow cover in the Loess Plateau, China

Using 8-day snow cover data of the Moderate Resolution Imaging Spectroradiometer from 2003 to 2013, we combined MOD10A2 and MYD10A2 to remove clouds and analysed the spatial and temporal variations of snow cover in the Loess Plateau, China. The snow cover throughout the entire Loess Plateau, including its central, southeast, and northwest sub-regions, exhibits consistent seasonal trends. The majority of snow cover is present from early November to late March, including four sub-cycles that involve separated snow cover accumulation and ablation processes. The maximum snow-covered area occurs in January with an areal extent of 1 242 000 km(2), whereas the minimum snow-covered area is observed from May to August. There is an evident relationship between snow cover distribution and elevation. The majority of snow cover is located in the central sub-region, whereas the lowest amount of snow cover exists in the northwest sub-region. In the examined 11 years, the snow cover area and snow cover days fluctuated considerably without a significant trend. A significantly negative correlation between snow cover and intra-annual temperature variation is observed. The monthly snow cover is found to correspond well with the Siberian High Central Intensity, particularly evident in November 2005, December 2007, December 2009, and December 2011. The response of the snow cover to the El Nino Southern Oscillation event was relatively weak, except for the significant cold event in late 2007 to early 2008 that caused a significantly positive snow cover anomaly.