Figure 8. The correlation between “AT –
CT” and AOU in surface water (depth ≤ 20 m) and deep
waters (depth > 100 m).
The green regression line intersects the y-axis at zero when AOU is at
its peak, aligning with predicted aerobic respiration, especially when
there is a notable increase in CT compared to
AT (Figures 7 and 8). In contrast, the black regression
line does not meet the zero line when AOU is elevated, as the data
influenced by anaerobic processes exerts an upward pull on the line.
This phenomenon is linked to processes that yield higher
AT and not solely CT, such as
CaCO3 dissolution (Xue and Cai, 2020) or anaerobic
processes like sulfate reduction and denitrification.