The R/V Bilim-2 left its port in the Mediterranean coast on 20th May 2023, and headed for the Marmara Sea. R/V Bilim-2’s Marmara cruise aim was to complete measurements along the SWOT satellite track, as well as conducting regular seasonal measurements for monitoring projects (e.g. pollution, mucilage, hypoxia).
R/V Bilim-2 started conducting measurements in the Aegean Sea, near the entrance of the Dardanelles Strait on 23th May, within IMS-METU’s regular seasonal sampling efforts. Biogeochemical measurements were also conducted, including dissolved oxygen, nutrients, phytoplankton and zooplankton. Vessel mounted ADCP, fluorometer and thermosalinograph (TSG, Figure2) gathered data continuously during the cruise. ADCP data are still under investigation. Satellite sea surface temperature (SST) image on 25 May 2023, clearly show (Figure 1) the inflow of cold Black Sea waters (i.e. Bosphorus Jet) and thus an east/west gradient in the center (~28.1o Longitude) of Marmara Sea.
After completing the stations on the Dardannelles strait, a CTD grid along the SWOT satellite track (Figure 1) consisting of 20 stations (~5km distance between stations) was completed on May 24, between 13:20-22:10 GMT. CTD grid was located north-west of Marmara Island (i.e. Marmara Adası) and on the main route of ships in the area.
Gridded surface temperature and salinity from CTD measurements are shown in Figure 2. Fine-scale gradients are evident, particularly in salinity. TSG measurements (Figure 2, bottom panel) and satellite SST (Figure 1) confirm these fine-scale gradients.