Physical oceanography and ADCP measurements during Maria S. Merian cruise MSM15/4

After the Eastern Mediterranean Transient (EMT), which occurred in the late 1980s, the abyssal water masses of the eastern Mediterranean were dominated by water masses of Aegean origin. Data from cruises carried out in recent years now indicate that the process of deep water formation has again been reversed, with Adriatic deep water being the main source for the deep water formation. The reversal of deep water production in the Ionian Sea is a long-term process and therefore it needs to be monitored over a period of years. The characteristics which are crucial for the deep water today, how it differs from the deep water before the EMT and in which state of the reversal it resides, these are the questions which have to be investigated continuously during the coming years. The cruises which have been accomplished (such as POS298, M71/3, MSM13/2) and the current one shall fulfill this purpose.

1980年代末发生的东地中海瞬变事件（Eastern Mediterranean Transient, EMT）后，东地中海东部海域的深渊水团曾以爱琴海源水团为绝对主导。近年科考航次获取的数据显示，深水形成过程已再度逆转，亚得里亚海深水成为当前深水形成的主要来源。爱奥尼亚海的深水生成逆转过程属于长期演变现象，因此需开展多年持续监测。当前深水团的关键属性、其与EMT发生前的深水团的差异，以及该逆转过程所处的阶段，均为未来数年需持续探究的核心科学问题。已完成的航次（如POS298、M71/3、MSM13/2）与当前正在执行的航次，均将围绕该研究目标开展工作。