No abstract

Snow cover is an essential sink of dissolved organic matter (DOM), directly affecting the carbon cycle (Antony et al., 2014). DOM related to microbes and the bioavailability may determine whether snow and ice are a net sink or source of CO 2 (Stibal et al., 2012). DOM released from snow/glacial runoff is an important source of labile reduced carbon to marine ecosystems, changing the age, quantity, and reactivity of DOM in coastal regions (Hood et al., 2009). Furthermore, snow cover reflects most sunlight, with reduced transmission due to the small size of snow grains and a multitude of air/ice interfaces (Perovich, 2007). DOM directly absorbs photons in the ultraviolet-visible region, changing the radiation balance of the snowpack, warming the atmosphere, and reducing snow albedo (Flanner et al., 2009;Grannas et al., 2007). DOM also plays an important role in producing reactive species and snow grains may also be conducive to enhance such process, more rapidly in frozen than liquid water states (Grannas et al., 2014). In addition to releasing reactive species, DOM, such as plant vascular material, is also involved in the photochemical production of CH 2 O and CH 3 CHO in snow (Grannas et al., 2004). Overall, above observations highlight the importance of the synergistic effects of snow and DOM.