Fig. 3: Seasonal cycle in sub-mixed layer oxygen dynamics at BATS.
From: Seasonal enhancement of the viral shunt catalyzes a subsurface oxygen maximum in the Sargasso Sea
Each point represents the mean oxygen saturation percentage for one of 5054 casts from BATS cruises where optode data matched Winkler method bottle calibrations (see Methods). The x-axis is the month of the year in which the BATS cruise took place, the y-axis is the mean oxygen saturation between the mixed layer depth and 10 m below the mixed layer depth, with mixed layer depth determined by a change in potential density of 0.125 kg/m3 from a reference pressure of 10 db. Point color indicates the calculated mixed layer depth of that cast. A nonlinear least squared fit of a sinusoidal regression was calculated and is shown as the red line. The model specification is: \({{\mathrm{mean}}}\left({O}_{2{{\mathrm{saturation}}}}\right)=a+{bsin}(2\pi*\left(c+{{\mathrm{mod}}}\left(\frac{{{\mathrm{decimal}}}{{\mathrm{year}}}}{12}\right)\right))\). Decimal year goes from 0 (Jan 1) to 1 (Dec 31). Estimated parameters with standard errors and p-values are: a = 1.020e + 02 std.error: 4.559e-02 p < 2e-16, b = −2.993e + 00 std.error:6.536e-02 p < 2e-16, c = 5.924e-01 std.error:3.376e-03 p < 2e-16.
