THE POST-1979 THERMOHALINE STRUCTURE OF THE DEAD-SEA AND THE ROLE OF DOUBLE-DIFFUSIVE MIXING

After centuries of meromixis (year-round stratification with a permanent halocline), the Dead Sea has passed through two distinct stages in the last decade: first a 4-yr meromictic stage and then a holomictic stage. In the first stage, classic one-dimensional processes dominated. In the second stage, three different regimes operated in a seasonal cycle: salt precipitation in spring and early summer, double-diffusive mixing in late summer and autumn, and vertical mixing in winter. During the second (holomictic) stage the Dead Sea as a whole also underwent secular changes: a gradual change in the salt composition of its brines, an increase of salt concentration, and a gradual heating.