Understanding how thermokarst lakes on arctic river deltas will respond
to rapid warming is critical for projecting how carbon storage and
fluxes will change in those vulnerable environments. Yet, this
understanding is currently limited partly due to the complexity of
disentangling significant interannual variability from the longer-term
surface water signatures on the landscape, using the summertime window
of optical spaceborne observations. Here, we rigorously separate
perennial lakes from ephemeral wetlands on 12 arctic deltas and report
distinct size distributions and climate trends for the two waterbodies.
Namely, we find a lognormal distribution for lakes and a power-law
distribution for wetlands, consistent with a simple proportionate growth
model and inundated fractal topography, respectively. Furthermore, while
no trend with temperature is found for wetlands, a statistically
significant decreasing trend of mean lake size with warmer temperatures
is found, attributed to colder deltas having deeper and thicker
permafrost preserving larger lakes.