Mixing with low-temperature and low-salinity water in the surface layer is a contributing factor to the decrease in water temperature in the sub-surface layer of the northeastern shelf margin of the Chukchi Sea (see Figure 6). The vertical shear of stratification strength and current velocity, which are indicators of mixing strength, showed that mixing was more likely to occur in Period 2 (2015-2019) than in Period 1 (2003-2005). It suggests that mixing with surface water was greater in period 2, resulting in a greater drop in water temperature.

Figure 6. Mixing with surface water (schematic diagram)
表層水との混合: mixing with surface water 低温低塩分水: low-temperature and low-salinity water 太平洋夏季水: Pacific Summer Water 表層: surface layer 亜表層: sub-surface layer