Fig. 3: Relationships between benzenepolycarboxylic acids (BPCAs) and apparent oxygen utilisation (AOU) in deep water (>27.5 σθ).
From: Fate of dissolved black carbon in the deep Pacific Ocean
a Relationship between the benzenetricarboxylic acids + benzenetetracarboxylic acid (B3CA + B4CA) concentration and AOU. The result of ordinary least squares regression was not significant (R2 = 0.132, p = 0.057, n = 28). The p value was derived from a two-tailed test. b Relationship between the benzenepentacarboxylic acid + benzenehexacarboxylic acid (B5CA + B6CA) concentration and AOU. Standard major axis regression was applied to determine the linear relationship between the B5CA + B6CA concentration and AOU and is shown as a black line. The 95% confidence interval (CI) determined for the slope and the intercept are also described in the figure. The result of ordinary least squares regression was as follows: [B5CA + B6CA] = −3.42 × 10−5 [AOU] + 0.0139 (R2 = 0.695, p < 0.001, n = 28). The p value was derived from a two-tailed test.
