Digital ACT Science Practice Question #1844

Why does the surface mixed layer (0 to 100 m) maintain a nearly uniform temperature (24.5°C to 23.8°C)? Experiment Context (Subtropical Oceanic Depth Profiles): An oceanographic research vessel lowered a CTD rosette probe to profile water temperature and salinity from the surface down to 2,000 meters depth in the Sargasso Sea: Table 30: - 0 m (Surface Mixed Layer): Temp = 24.5°C; Salinity = 36.6 PSU; Density = 1,024.2 kg/m^3 - 100 m (Base of Mixed Layer): Temp = 23.8°C; Salinity = 36.5 PSU; Density = 1,024.4 kg/m^3 - 300 m (Main Thermocline): Temp = 17.2°C; Salinity = 36.2 PSU; Density = 1,026.1 kg/m^3 - 700 m (Main Thermocline): Temp = 10.1°C; Salinity = 35.4 PSU; Density = 1,027.2 kg/m^3 - 1,000 m (Deep Water): Temp = 5.2°C; Salinity = 35.0 PSU; Density = 1,027.7 kg/m^3 - 2,000 m (Abyssal Zone): Temp = 2.4°C; Salinity = 34.9 PSU; Density = 1,027.9 kg/m^3