Rossby waves driven by the Mid Mediterranean Jet impact the Eastern Mediterranean mesoscale dynamics

Area of Science:

• Oceanography
• Fluid Dynamics
• Physical Oceanography

Background:

• The eastern Mediterranean Levantine Basin (LB) features a prominent warm anticyclonic Cyprus Eddy (CE) above the Eratosthenes Seamount (ESM).
• The formation and dynamics of the CE and associated eddies (SSE, NSE) are debated, impacting LB upwelling and productivity.

Purpose of the Study:

• To investigate the formation mechanism of the Cyprus Eddy (CE), South Shikmona Eddy (SSE), and North Shikmona Eddy (NSE).
• To understand the impact of these eddies on the Levantine Basin's oceanographic dynamics and biological productivity.

Main Methods:

• Multi-approach research including theory, numerical modeling, laboratory experiments, and field observations.
• Analysis of the interaction between the Mid-Mediterranean Jet (MMJ) and the Eratosthenes Seamount (ESM).

Main Results:

• The CE is identified as an anticyclonic Taylor column generated by the MMJ impinging on the ESM.
• The formation of SSE and NSE is linked to the CE's position west of 32.7° E, forming a downstream Rossby wave.
• CE position depends on MMJ intensity, influenced by the North Ionian Gyre's mode.

Conclusions:

• The study elucidates the generation mechanism of key eddies in the Levantine Basin.
• Findings enable prediction of Eastern Mediterranean Sea mesoscale dynamics up to three years in advance.
• Identified Rossby wave mechanism facilitates offshore nutrient transport, crucial for the LB's oligotrophic environment.