[Abstract]

The penetration of visible solar radiation (VSR) in the upper ocean contributes to heating in the upper water column and this impact is modulated by constituents in water such as phytoplankton. Various schemes have been developed to propagate surface VSR to deeper depths and incorporated in ocean circulation models to study the basin scale impacts on ocean and atmosphere by phytoplankton, but no studies have ever evaluated if the results are immune to schemes of VSR transmission. We here thus use an idealized one-dimensional (1-D) Regional Ocean Modeling System (ROMS) to simulate profiles of upper column temperature at six stations with different ocean color characteristics (containing different water constituents). We incorporated and tested four different schemes for VSR transmission, which include the default water-type scheme within ROMS, two schemes based on concentrations of chlorophyll (Chl), and one scheme based on water’s inherent optical properties (IOPs). The results show that, although all model runs used the same ocean color information and the same circulation model, the IOPs- and Chl-based schemes resulted in very different vertical temperature and upper water mixing from the standard scheme, where the difference in sea surface temperature can be up to 1.5~2 °C. These results highlight the importance of developing and incorporating more appropriate VSR transmission schemes for large-scale ocean circulation simulations where the inputs for such transmission are inherently estimates from ocean color, which is the actual measurement from satellite remote sensing.

Monthly MLD from the four light transmission models of Stations 1 – 6 and the difference of MLD between new models and PS77

Liu, TT; Lee, ZP; Shang, SP; Xiu, P; Chai, F; Jiang, MS. Impact of Transmission Scheme of Visible Solar Radiation on Temperature and Mixing in the Upper Water Column With Inputs for Transmission Derived From Ocean Color Remote Sensing. Journal of Geophysical Research-Oceans, 2020, 125(7).