Numerical simulation of summer warming of Siberian shelf seas depending on short-wave radiation parameterization
D.F. Iakshina, E.N. Golubeva, V.S. Gradov
Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the RAS, Novosibirsk, Russia
Keywords: numerical simulation, Siberian Shelf seas, parameterization of short-wave radiation, chlorophyll concentration, Arctic ocean
Abstract
The main source of summer heating of the upper layer of the Siberian Arctic shelf seas is shortwave solar radiation. The radiation flux attenuates as it passes through the water column, and the attenuation rate is determined by the optical properties of water, depending mainly on the concentration of suspended matter in the water. In numerical models of the ocean and sea ice, the process of absorbation of shortwave solar radiation is described by various parameterizations. In the present work, the sensitivity of the regional 3D numerical ocean and sea ice model SibCIOM to two parameterizations of the penetrating radiation is studied: (1) two-component parameterization using constant attenuation coefficients for the infrared and visible parts of the spectrum depending on one of the 10 transparency classes of ocean waters; (2) a three-component one, with different absorption coefficients for the red, green, and blue parts of the visible spectrum and relying on satellite data on chlorophyll concentration. Analysis of the results of numerical experiments for the water area of the Siberian shelf seas has shown that taking into account the seasonal distribution of chlorophyll concentration when forming the flux of penetrating shortwave radiation leads to the formation of regions of water warming in the surface or bottom layer, which differ from the basic experiment with two-component parameterization.
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