Evolution of the specific surface area and of crystal morphology of Arctic fresh snow during the ALERT 2000 campaign

摘要

Metamorphism of surface snow results in a decrease in specific surface area (SSA), which causes the release of adsorbed trace gases. This process contributes to the impact of the snowpack on atmospheric chemistry and must be quantified. The SSA evolution of fresh snow layers was measured in February and April 2000 during the ALERT 2000 campaign at Alert (Canadian Arctic: 82°29′94″N, 62°20′55″W). Measurements were made using CH_4 adsorption at 77K. Numerous photomacrographs of snow crystals were also taken to interpret observed SSA decreases. Five snowfalls were studied.