Marine diffusive boundary layers at high latitudes

The thickness of marine diffusive boundary layers (DBLs) can be calculated from the friction velocity and the water density (a function of temperature and salinity). However, DBL thickness scales differently with temperature, depending on whether free-stream or friction velocity is used. We show that there are advantages to using frictional velocity for experimental scaling. Low seawater temperatures in polar areas cause DBLs to be up to 32% thicker than in temperate or tropical areas. This will have a significant effect on biological processes such as photosynthesis and respiration.