Fig. 1.

Mass and carbon fluxes. Flux profiles of a mass, b total carbon (TC), and c organic carbon (OC). The magenta curves are the best fits to a log–log transformed normalized power function of the form F_z = F₁₀₀ (z/100)^b where F_z is flux at depth z(m), F₁₀₀ is flux at 100 m and b is the coefficient of flux attenuation (ref. ¹¹; Supplementary Fig. 1). The best fit parameters are: mass flux, F₁₀₀ = 158.5 mg m⁻² d⁻¹, b = −0.60, r² = 0.85; TC flux, F₁₀₀ = 45.71 mg C m⁻² d⁻¹, b = −0.80, r² = 0.93; OC flux, F₁₀₀ = 42.66 mg C m⁻² d⁻¹, b = −0.89, r² = 0.93. Vertical fluxes of d OC, e IC and f BC expressed as percentages of TC for each depth