Noun
halocline (plural haloclines)
a strong, vertical salinity gradient; the (sometimes indistinct) border between layers of water that contain different amounts of salt
During the spring, the Batumi eddy forms in the southeastern corner of the sea. citation Beneath the surface waters—from about 50–100 meters—there exists a halocline that stops at the Cold Intermediate Layer (CIL). Source: Internet
The upper layer has a salinity between 18‰ and 26‰ and the lower layer - separated by a strong halocline at around 15 meters -, has a salinity between 32-34‰. Source: Internet