Greenland ice sheet runoff reduced by meltwater refreezing in bare ice.

ABSTRACT: The contribution of Greenland Ice Sheet meltwater runoff to global sea-level rise is accelerating due to increased melting of its bare-ice ablation zone. There is growing evidence, however, that climate models overestimate runoff from this critical area of the ice sheet. Climate models traditionally assume that all bare-ice runoff enters the ocean, unlike porous firn, in which some meltwater is retained and/or refrozen. We used field measurements and numerical modeling to reveal that extensive retention and refreezing also occurs in bare glacier ice. We found that, from 2009 to 2018, meltwater refreezing in bare, porous glacier ice reduced runoff by an estimated 11-17 Gt a^-1 in southwest Greenland alone, equivalent to 9-15% of this sector's annual meltwater runoff simulated by c

SUBMITTER: Cooper MG 

PROVIDER: S-EPMC12432254 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature