Spatial and temporal variations of snow cover in the forest area of middle and high latitude of Northern Hemisphere

Abstract

Snow cover is an important part of cryosphere and the most seasonally changing land surface cover, which is sensitive to climate change. Previous studies showed that climate warming has already altered the extent and phenology of snow cover, which influences the plant phenology of the forest ecosystem. This research investigates the spatial distribution and temporal trend of snow cover in the forest area of mid and high latitude in the Northern Hemisphere (50°N-90°N,180°W-180°E) based on a satellite-derived snow dataset. Results showed that the spatial distribution of snow cover exhibits a latitudinal gradientin the mid and high latitudes of the Northern Hemisphere. The snow cover onset week (SCOW) and snow cover end week (SCEW) shortened significantly at a rate of 0.23 weeks/10 yr. and 0.48 weeks/10 yr., respectively (P<0.05). Cold season (CS) and snow cover persistence week (SCPW) shortened at a rate of 0.25 weeks/10 yr. and 0.16 weeks/10 yr. 19.62% of the study area showed a trend of a significant advance in SCOW, and 1.36% showed a trend of significant delay (P<0.05). For SCEW, 44.91% of regions showed significant advance and 1.91% of regions showed significant delay (P<0.05). CS was a significantly shorted trend (P<0.05) in 16.95% of the study area and showed a significantly extended trend (P<0.05) in 3.76% of the area. SCPW and CS were similar but different, indicating that transient snowfall exists in parts of the study area.