Figure 5. Within and between day variability in UVP predicted particle flux at ETNP Station P2. All profiles are depth binned with higher resolution towards the surface (methods). Horizontal blue lines indicate the top and bottom of the ODZ, while the horizontal green line indicates the base of the photic zone. A. Flux profiles in the top 1000 m of the water column. B. A more detailed depiction of the area enclosed by the rectangle in A . – C. The rate of change of flux, divided by the rate in change in depth. The fifth root of these values are shown to highlight differences between values close to zero. Hour corresponds to local, Mexican General Standard, time.

Smoothed and averaged data

At the ETNP ODZ site, highly smoothed particle abundance data suggested that particle size, averaged across all casts, followed a pattern in which the abundance of <500 μm particles increased between the oxycline and 350 m (Figure 6A), which corresponded with steepening of the particle size distribution slope (Figure 6B), and an increase in microaggregate (<500 μm) particle biomass (Figure 6C), but not of > 500 μm particle biomass (Figure 6D). Deeper in the ODZ, the microaggregate (<500 μm) particle number and biomass, and the particle size distribution slope declined.