Annual MLT

The annual vertically averaged lake water temperature (MLT) was 5.11, 3.55, and 3.35 ◦C in NL, D1F, and HSP respectively (Figure 4b). The annual MLT of HSP was the lowest because of the stronger heat loss from the open surface of HSP in winter compared to the ice-covered NL and D1F.

The annual NL MLT increased by 0.19 ◦C/decade, i.e., much slower than the annual LSWT in NL (0.68 ◦C/decade) and slower than the annual MLT trends in D1F (0.54 ◦C/decade) and HSP (0.56 ◦C/decade) (Figure 4). Apparently, the MLT of the deep lake increased more slowly due to its large heat capacity and thermal inertia. Salinity differences between shallow lakes D1F and HSP did not have a strong influence on the observed MLT trend.
