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. 2021 Sep 22;11:18804. doi: 10.1038/s41598-021-97731-4

Table 2.

Mean ± standard deviation of selected variables.

Variables (units) T M G A K-W pvalue Post hoc Bonferroni
SST (ºC) 26 ± 3 16 ± 4 16 ± 2 0.1 ± 1.0  < 0.001 T > M,G,A; G > A
SSS (PSU) 36 ± 1 38 ± 0.1 35 ± 0.4 34 ± 0.9  < 0.001 M > T,G > A
maxN2 × 10–4 (s−2) 7 ± 7 3 ± 5 11 ± 12 4 ± 10  < 0.001 G > T > M,A
dmaxN2 (m) 74 ± 43 35 ± 17 16 ± 14 94 ± 92  < 0.001 T > M > G; A > G
avrN2 × 10–4 (s−2) 2.1 ± 3 0.7 ± 0.5 1.9 ± 1.4 0.3 ± 0.6  < 0.001 G > T,M,A; T > A
MLD (m) 53 ± 23 32 ± 29 15 ± 13 174 ± 198  < 0.001 T,A > M,G
K × 10–3 (m2 s−1) 0.03 ± 0.05 2 ± 6 0.4 ± 0.5 66 ± 126  < 0.001 M,G,A > T
nitraD (m) 109 ± 59 9 ± 12 9 ± 16 5 ± 0  < 0.001 T > M,G,A
grNO3 (µmol m−4) 142 ± 149 92 ± 37 124 ± 86 42 ± 29  < 0.05 T,G > A
sNO3 (mM) 0.5 ± 1.2 2.3 ± 1.7 1.7 ± 1.7 31 ± 4  < 0.001 M,G,A > T; A > G
dNO3 (mmolN m−2 d−1) 0.4 ± 1.0 39 ± 110 5.3 ± 7.1 102 ± 165  < 0.001 M,G,A > T
TNO3 (mmolN m−2 d−1) 0.4 ± 1.0 39 ± 110 31 ± 42 102 ± 165  < 0.001 M,G,A > T
DCM (m) 100 ± 32 41 ± 20 16 ± 11 54 ± 24  < 0.001 T > M > G; A > G
maxCHL-a (mg m−3) 0.5 ± 0.2 1.1 ± 0.9 4.3 ± 3.7 1.3 ± 0.8  < 0.001 G > T,M,A
sCHL-a (mg m−3) 0.2 ± 0.1 0.9 ± 0.9 2.5 ± 2.9 1.1 ± 0.8  < 0.001 M,G,A > T
PP (mgC m−2 d−1) 202 ± 98 581 ± 454 2950 ± 2330 153 ± 136  < 0.001 G > T,A; M > T

Sea surface temperature (SST), sea surface salinity (SSS), vertical stratification in the pycnocline (maxN2), depth of the pycnocline (dmaxN2), average stratification in the nitracline (avrN2), depth of the mixed layer (MLD), vertical turbulent diffusivity (K), depth of the nitracline (nitraD), nitrate gradient across the nitracline (grNO3), surface nitrate concentration (sNO3), diffusive nitrate supply (dNO3), total nitrate supply (including diffusive and advective fluxes, TNO3), depth (DCM) and value (maxCHL-a) of the maximum chlorophyll-a, surface chlorophyll-a (sCHL-a), and photic layer depth-integrated net primary production (PP), computed for the tropical and subtropical regions (T), the Mediterranean Sea (M), the Galician coastal upwelling (G), and the Antarctic Peninsula (A). A nonparametric one-way ANOVA (Kruskal–Wallis, KW) was performed to test the null hypothesis that independent groups come from the same distribution. The Bonferroni multiple comparison test was applied a posteriori to analyze the differences between every pair of groups.