Lake changes and their driving factors in circum-arctic permafrost regions from 1990 to 2022

Abstract

The rapid increase in temperatures and escalating human activities have led to a reduction or even disappearance of the thickness of the permafrost layer around the Arctic. Meanwhile, the degradation of permafrost has impacted the ecosystems within the circum-Arctic permafrost regions, also triggering a series of geological environmental changes. Consequently, research in the circum-Arctic permafrost regions is crucial not only for understanding the impact of climate change on the cryosphere but also for predicting and managing future environmental changes in the area. In this study, we extracted the number of lakes and their areas within certain areas of the circum-Arctic permafrost region from 1990 to 2022, and further investigated the factors driving lake changes. Analysis revealed a stabilization of lake areas in continuous permafrost regions, expansion in discontinuous and sporadic permafrost, and reduction in isolated permafrost, indicating the significant impact of global warming on the degradation of discontinuous and sporadic permafrost, while continuous permafrost remains less affected. Lake area dynamics across various permafrost types were influenced by distinct factors: in discontinuous permafrost, lake expansions correlated positively with snowfall, rainfall, snowmelt, and evapotranspiration; in sporadic permafrost, area reductions were tied to temperature increases, despite positive correlations with snowmelt and evapotranspiration; and in isolated permafrost, lake contractions were negatively associated with air temperature. Furthermore, permafrost degradation notably influenced lake area changes, especially in sporadic and isolated permafrost, where an inverse relationship between lake area and temperature was observed.