Factors governing the deep ventilation of the Red Sea

A variety of data based on hydrographic measurements, satellite observations, reanalysis databases, and meteorological observations are used to explore the interannual variability and factors governing the deep water formation in the northern Red Sea. Historical and recent hydrographic data consistently indicate that the ventilation of the near-bottom layer in the Red Sea is a robust feature of the thermohaline circulation. Dense water capable to reach the bottom layers of the Red Sea can be regularly produced mostly inside the Gulfs of Aqaba and Suez. Occasionally, during colder than usual winters, deep water formation may also take place over coastal areas in the northernmost end of the open Red Sea just outside the Gulfs of Aqaba and Suez. However, the origin as well as the amount of deep waters exhibit considerable interannual variability depending not only on atmospheric forcing but also on the water circulation over the northern Red Sea. Analysis of several recent winters shows that the strength of the cyclonic gyre prevailing in the northernmost part of the basin can effectively influence the sea surface temperature (SST) and intensify or moderate the winter surface cooling. Upwelling associated with periods of persistent gyre circulation lowers the SST over the northernmost part of the Red Sea and can produce colder than normal winter SST even without extreme heat loss by the sea surface. In addition, the occasional persistence of the cyclonic gyre feeds the surface layers of the northern Red Sea with nutrients, considerably increasing the phytoplankton biomass

Sensing coral reef connectivity pathways from space

Coral reefs rely on inter-habitat connectivity to maintain gene flow, biodiversity and ecosystem resilience. Coral reef communities of the Red Sea exhibit remarkable genetic homogeneity across most of the Arabian Peninsula coastline, with a genetic break towards the southern part of the basin. While previous studies have attributed these patterns to environmental heterogeneity, we hypothesize that they may also emerge as a result of dynamic circulation flow; yet, such linkages remain undemonstrated. Here, we integrate satellite-derived biophysical observations, particle dispersion model simulations, genetic population data and ship-borne in situ profiles to assess reef connectivity in the Red Sea. We simulated long-term (>20 yrs.) connectivity patterns driven by remotely-sensed sea surface height and evaluated results against estimates of genetic distance among populations of anemonefish, Amphiprion bicinctus, along the eastern Red Sea coastline. Predicted connectivity was remarkably consistent with genetic population data, demonstrating that circulation features (eddies, surface currents) formulate physical pathways for gene flow. The southern basin has lower physical connectivity than elsewhere, agreeing with known genetic structure of coral reef organisms. The central Red Sea provides key source regions, meriting conservation priority. Our analysis demonstrates a cost-effective tool to estimate biophysical connectivity remotely, supporting coastal management in data-limited regions

Numerical modeling of oil pollution in the Eastern Mediterranean sea

This chapter presents a summary of major applications in numerical oil spill predictions for the Eastern Mediterranean Sea. Since the trilateral agreement between Cyprus, Egypt, and Israel back in 1997, under the framework of the subregional contingency plan for preparedness and response to major oil spill pollution incidents in the Eastern Mediterranean Sea, several oil spill models have been implemented during real oil pollution accidents and after oil spills that were detected from satellite remote sensing SAR data. In addition, several projects cofinanced by the European Commission addressed particularly issues with oil spill modeling, taking the advantage of developments in operational oceanography, as well as collaboration with the Mediterranean Oceanographic Network for Global Ocean Observing System (MONGOOS), with the European Maritime Safety Agency CleanSeaNet (EMSA-CSN), and Regional Marine Pollution Emergency Response Centre for the Mediterranean Sea (REMPEC). Major oil pollution incidents in the Eastern Mediterranean and the oil spill modeling applications carried out are summarized in this work. Three well-established operational oil spill modeling systems – two of them characterized by different numerical tools MEDSLIK, MEDSLIK II, and the POSEIDON oil spill models – are described in terms of their applicability to real oil spill pollution events, the Lebanon oil pollution crisis in summer 2006, the case Costa Concordia accident, and the spill event associated with the collision of two cargo vessels in the North Aegean Sea in June 2009. Finally, an overview of the present-day capability of Eastern Mediterranean countries in oil spill modeling is provided in this chapter