International Journal of Molecular Ecology and Conservation, 2025, Vol.15, No.6, 277-285 http://ecoevopublisher.com/index.php/ijmec 279 Figure 1 The Jaridge ridge and adjacent lead in summer 2020 (Adopted from Nicolaus et al., 2022) Image caption: (A) Approximate surface elevation of the sea ice or snow surface from airborne laser scanning on June 30, 2020; (B) Bottom topography from the multibeam sonar on the remotely operated vehicle (ROV) Beast on June 25, 2020; (C) Surface photography on July 04, 2020; and (D) Surface photography with surface installations and Polarstern in the background on July 21, 2020. In (B) the location of the ROV hut, sediment trap deployment, IMB (2020M26) deployment, and the approximate views of C and D are indicated. The dashed lines indicate the locations of consecutive drilling transects across the ridge (Adopted from Nicolaus et al., 2022) In addition, the optical properties of snow cover, especially albedo, play a crucial role in the surface radiation balance. The albedo of fresh snow can be as high as 0.85, while that of snow with impurities, old snow or in the melting stage will significantly decrease to 0.4 or even lower. Albedo changes not only affect local energy budgets but also participate in the global climate feedback process. The water content within the snow (solid and liquid) determines the energy storage capacity of the snow and the rhythm of meltwater release, thereby affecting the spring flood peak and seasonal river recharge (Richardson et al., 2024). 2.3 Spatiotemporal variation characteristics of snow cover The strong seasonal and geographical differences of snow cover in terms of time and space are the core sources of the complexity of its ecological functions. Snow cover in the Northern Hemisphere shows a typical pattern of expansion in winter and contraction in summer. However, on a regional scale, high-latitude tundra, boreal forests and mountainous areas exhibit highly differentiated snow cover dynamics. For instance, in the mid-high latitudes of Eurasia, the thickness of winter snow cover has shown a weak upward trend in the past 40 years, while the duration of spring snow cover has significantly shortened. The Rocky Mountains in North America showed significant changes such as a decrease in snow water equivalent and an earlier snowmelt (Lathrop et al., 2024). The key mechanisms by which climate warming drives the spatio-temporal changes of snow cover include: temperature rise leading to the transformation of snowfall into rainfall, an increase in warm winter events causing the snow layer to melt more easily, and a delay in the formation period and an advance in the melting period of snow cover. Meanwhile, extreme climate events - such as sudden cold air or extreme snowfall - make snow cover changes unstable. Under the background of global warming, the overall trend of the spatio-temporal pattern of snow cover is "reduction, thinning and premature melting", but in some local areas, reverse changes may occur due to abnormal climate and atmospheric circulation. 3 The Regulatory Role of Snow Cover on the Ecosystem 3.1 Energy balance and climate feedback Snow cover reflects a large amount of short-wave radiation back to the atmosphere through high albedo and is a key factor in regulating the energy balance of the earth's surface. The variation of snow cover area can directly
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