Evaluating interdependencies of lake water surface temperature and clarity

Lakes are crucial components of environmental systems, playing a significant role in maintaining ecological balance, influencing hydrological processes, and affecting regional climates. This study investigates the relationship between water clarity and lake water surface temperature (LWST) across various climate zones, utilizing data from 1982 lakes obtained from Landsat 7 and ERA5-Land datasets. The study employed dynamic water extent analysis to derive the color, turbidity, and temperature of the lakes. Based on Forel-Ule Index (FUI) classification, the lakes were categorized into high clarity lakes, moderate clarity lakes, and low clarity lakes. The Peter and Clark Momentary Conditional Independence (PCMCI) framework was used to identify causal relationships between water clarity and LWST. The findings revealed that 15 out of 19 climate zones demonstrated a causal relationship between water clarity and LWST. Furthermore, when comparing different classes of lakes, 86.67 % of climate zones showed consistent results, with lakes of low clarity generally exhibiting larger increases in surface temperatures when compared to high clarity lakes.