part of has part has input has output causally upstream of permafrost water ice hydrological melting process meltwater permafrost thawing process warming of a liquid warming of a solid hydrological process ice-bearing permafrost thawing process http://orcid.org/0000-0002-3410-4655 envoPolar A permafrost thawing process during which water-based ice or snow present in permafrost is converted into meltwater. methane gas emission process