4th year PhD student
Advisor: Jade Morton
Lab: Satellite Navigation and Sensing Laboratory
Permafrost is undergoing rapid change due to the warming arctic climate. Permafrost lies beneath more than a quarter of the Northern Hemisphere, and its degradation can be gradual or abrupt. Abrupt thaw processes happen on timescales of days or weeks, and are characterized by dramatic landscape changes such as land subsidence, wetland formation, and lake drainage. However, significant uncertainty remains regarding abrupt permafrost thaw, such as (1) uncertainty in differentiating between lakes and wetlands in current datasets (which have unique methane emissions), (2) understanding how quickly thaw lakes and wetlands drain, and (3) estimating the rate at which lakes will be invaded by wetland vegetation in the drainage process (emissions off-setters). The goal of this research is to fill the knowledge gaps surrounding abrupt thaw processes by generating high-resolution maps of thermokarst wetlands and lakes using GNSS-Reflectometry (GNSS-R) measurements in the permafrost underlain regions of North America on biweekly, seasonal, and inter-annual timescales. Spaceborne GNSS-R is uniquely positioned to improve thermokarst wetland and lake mapping given its high spatial resolution, short revisit time, and ability to penetrate vegetation and clouds. Many previous studies have demonstrated GNSS-R’s capability in sensing water-related processes, such as small inland water body detection, with it outperforming other missions’ water detection under dense vegetation. This specifically attests to the merit of GNSS-R for thaw-related applications as boreal forests cover most sub-arctic permafrost regions.