CTD vertical profiles along two corridors in the Ionian Sea, running W-E (from the Sicily Channel to the Matapan Trench) and NE-SW (from the Matapan Trench, across the Mediterranean Ridge, up to the Syrte Basin), respectively

Temperature of the water column

Discrete water samplers; CTD

The CTD apparatus is widely used to register, with continuous vertical records, the main physical parameters of the water column. Sensors are fully calibrated, allowing to easely compare data acquired using different instruments. In the URANIA 15/97 cruise, CTD allowed for delimiting in space the actual extension of the transient climatic event in the Ionian Sea waters and monitoring in time its evolution, comparing actual data with those acquired in 1993. Data acquisition was made at 24 Hz frequency, during descent only, at a constant speed of about 1 m/s. Detailed monitoring of the brines in the brine lakes of the Mediterranean Ridge was also attempted. The instrumental configuration was always maintained as indicated in '*INSTRUMENTS' (CTD SeaBird + additional sensors), except in brines, where the CTD Idronaut, although less accurate than the SeaBird, offered the advantage of a larger range in measuring salinity. In addition to standard sensors, the CTD SeaBird apparatus is equipped also with a polarographic cell for measuring the dissolved oxygen content in water. The cell is crossed by a light electric current (of the order of m A), proportional to the amount of oxigen diffusing through a teflon wall.

National Institute of Oceanography and Applied Geophysics - OGS, Division of Oceanography
Borgo Grotta Gigante 42/c
Sgonico (Trieste)

34010
Italy