Speaker 1: Dr. Malika Kheireddine
Title: Trophic regimes of the Red Sea: a satellite analysis (preliminary results)
Abstract: Until now, in situ sampling of the Red Sea remains a challenge. Partitioning of the Red Sea using a cluster method based on satellite surface chlorophyll concentration could help to identify homogeneous bioregions and guide future in situ sampling. Thus, sixteen years of satellite surface chlorophyll concentration observations, presently available, were used to characterize the biogeography of the Red Sea and the resulting seasonal cycle of phytoplankton for each of the bioregions. A K-means cluster analysis has been applied to the time-series of satellite-derived chlorophyll concentration. Five significate bioregions were found based on climatological seasonality (phenology) of the phytoplankton. These 5 bioregions are linked to the biophysical-interactions observed in their respective regions. For example, the northern region is characterized by a distinct winter-time phytoplankton bloom resulting from deep mixing events. In contrast, the most southern bioregion is characterized by a summer phytoplankton bloom when nutrient-rich water from the Gulf of Aden intrudes into the southern Red Sea in response to the southwest monsoon. The resulting coherent patterns for each bioregion need to be explained based on the knowledge of the basin's functioning and modeling.
Speaker 2: Dr. Lohitzune Solabarrieta
Title: Applications of High Frequency Radar Measurements of Surface Currents for Scientific and Applied Efforts
Abstract: Two (2) High Frequency (HF) Radar systems, situated at KAUST and Rabigh since 2017, measure real time hourly surface currents up to 100km from the coast (nearly 8000 sq. km) with 3km spatial resolution. This dataset allows us to describe the seasonal variability of the surface currents in the central Red Sea and to extract the Mixed Layer Depth (MLD) from the whole study area, combining HF Radar and wind data. Moreover, a 'quasi-permanent' glider line has also been running under the HF Radar footprint for approximately 1 year, enabling us to validate the MLD estimated from the HF Radar data.
An Automated Identification System (AIS) antenna, located at the Rabigh site, simultaneously receives ship positions, speed and bearing. The high spatio-temporal resolution of the HF Radar data enables us to simulate the backtracking of drifting surface particles. The combination of the backtracking of the particles and the AIS data allow us to identify likely sources of detected oil spills, and an operational system could subsequently be established. This would reduce illegal oil discharge incidents as ship owners would know that their discharges could be backtracked to their vessels, enabling the Coast Guard to levy appropriate sanctions in response to such incidents.