Understanding how finescale processes interact in water mixing at the interface between Black Sea water and Mediterranean Sea water.
The Marmara Sea is characterized by peculiar oceanographic processes. Cold, fresh Black Sea water entering through the Bosporus meets warm and salty water of Mediterranean Sea origin flowing in through the Dardanelles Strait. This creates the situation where fresher water is located near the surface and much saltier water near the bottom.
The Marmara Sea is highly populated (~22 million people) and at risk of large-scale anoxic events caused by severe eutrophication. The overall surface flow is westward from the Bosporus towards the Dardanelles Strait, with well-defined anticyclonic gyres. The upper layer currents respond very rapidly to the direct and indirect effect of wind forcing. This creates a unique environment of strong mesoscale activity, whose finescale dynamics is still poorly known.
The Marmara Sea campaign improved the characterization of oceanic mesoscale and sub mesoscale features (fronts, meanders, eddies and filaments) through the combined use of in situ and satellite data in synergy with numerical models in this highly inhabited region.
Ship-borne studies took place for 2×1 week using underway CTDs and ScanFish on institute owned and operated research vessel R/V Bilim 2 during phytoplankton bloom times. SWOT SSH data were used in modelling efforts to investigate the impacts of mesoscale eddies on bloom dynamics and consequent anoxic events. The circulation model NEMO coupled to the ERSEM ecosystem model was be used.
The Marmara Sea campaign contributed to understanding mesoscale and sub mesoscale processes in the Marmara Sea and their influence on bloom dynamics and consequent anoxic events, a phenomenon of growing importance in many of the world seas.
Investigating the role of fine scale processes in horizontal exchange and impacts on phytoplankton in the Black Sea
The Black Sea is the largest body of anoxic water on earth, and it is also one of the fastest warming seas. It is strongly influenced by the high amount of fresh water input from major European rivers into the sea. The upper ocean dynamics are critical for the ventilation of the upper layer of the Black Sea. Understanding the role of fine scale processes on the circulation and ecosystem are crucial to assess the well-being of this land-locked marginal sea.
The general circulation of the Black Sea is characterized by a wind-driven, bathymetry stirred, cyclonic boundary current (i.e., Rim Current). Mesoscale and submesoscale variability is strong, particularly during weak phases of the boundary current. The Black Sea campaign will focus on the western Black Sea, where the boundary current meets complex topography and Mediterranean Sea waters injected through the Bosphorus Strait. Therefore, eddies, filaments and meanders of the boundary current are often observed, which contribute to cross-shelf transport as well as increased productivity. The Black Sea campaign focused in this region, and aimed to unravel the contribution of these fine scale processes.
Principal investigators: B. Fach (bfach@ims.metu.edu.tr), H. Orek (orek@ims.metu.edu.tr), Anıl Akpinar (anil@ims.metu.edu.tr)
Institutes involved in the campaign: Institute of Marine Science, Middle East Technical University
Contact point for the study site: Bettina Fach (bfach@ims.metu.edu.tr)
Checkout the Marmara Sea and Black Sea blog!
