Modeling a century of change: Kangerlussuaq Glacier's mass loss from 1933 to 2021

Kangerlussuaq Glacier, a dominant contributor to mass loss in central-eastern Greenland, has primarily been studied using remote sensing methods, whose mass balance over the last century and specific drivers of change remain poorly understood. We introduce a novel approach that combines numerical modeling and a 1933-2021 climate forcing to reconstruct its mass balance over the past century. The model's final state aligns remarkably well with present-day observations. It reveals a total ice mass loss of 285 Gt over the century, equivalent to 0.68 mm global sea level rise, $51\%$ of which occurred since 2003 over the last 20 years alone. Notably, dynamic thinning from ice front retreat is responsible for $88\%$ of mass change since 1933, with seasonal ice front variations having minimal impact on centennial mass loss. Compared to earlier studies, our findings suggest that Kangerlussuaq lost 301 Gt (59\%) less mass over the century than previously thought.