Fig. 4: Diagnosed latent heat flux and vertical ocean currents during CE2L onset.

a Diagnosed latent heat flux (\({{lh}}^{{\prime} }\)) and its linearized components averaged over (5°S–5°N, 120°–80°W) during JF(0) for CE2L (units: °C mon⁻¹). “wind_anom”, “q_anom” and “wind_q_anom” represent the components \(-{\rho }_{a}{C}_{E}{L}_{v}{\left|U\right|}^{{\prime} }\overline{\left({q}_{s}-{q}_{a}\right)}\), \(-{\rho }_{a}{C}_{E}{L}_{v}\bar{U}{\left({q}_{s}-{q}_{a}\right)}^{{\prime} }\), and \(-{\rho }_{a}{C}_{E}{L}_{v}{\left|U\right|}^{{\prime} }{\left({q}_{s}-{q}_{a}\right)}^{{\prime} }\), respectively. b Anomalous vertical ocean current (\({w}^{{\prime} }\)) at the bottom of the mixed layer (units: \({3\times 10}^{-5}\ m\ {s}^{-1}\)), mixed-layer averaged divergence (\({{DIV}}^{{\prime} }\)), divergence calculated by geostrophic currents (\({{{DIV}}_{g}}^{{\prime} }\)), divergence calculated by Ekman currents (\({{{DIV}}_{e}}^{{\prime} }\)), zonal component of \({{{DIV}}_{e}}^{{\prime} }\), and meridional component of \({{{DIV}}_{e}}^{{\prime} }\) (units: \({10}^{-6}\ {s}^{-1}\)) averaged over (5°S–5°N, 120°–80°W). The error bars in a, b represent one standard deviation. Orange solid dots denote statistically significant terms. Horizontal distribution of anomalous c vertical ocean current at the bottom of the mixed layer (units: \({3\times 10}^{-5}\ m\ {s}^{-1}\)) and d mixed-layer averaged horizontal divergence (shaded, units: \({10}^{-6}\ {s}^{-1}\)) and ocean currents (vector, units: \(m\ {s}^{-1}\)). Green dots in c, d represent the anomalous vertical ocean current and horizontal divergence that exceed the 95% confidence level.