In the Mediterranean, a glider regularly "travels" the Ligurian Sea.
According to the glider’s autonomy and depending on the measurement cycles, a mission usually lasts about six weeks.
It is organized in two main parts:
(1) a so-called “medium-resolution” transect and
(2) “high-resolution” transects.
At first, the glider goes from Villefranche-sur-mer (French Riviera) to Calvi (Corsica), and back. During this transect, the glider operates between sea surface and 1000 meters water depth. The sensors are activated only during ascent. This “medium-resolution” transect allows to monitor, on a monthly basis, the main hydrographic and biogeochemical features of the Ligurian basin.
Subsequently a series of “high-resolution” transects follows: the glider runs between Villefranche-sur-mer and the Boussole / Dyfamed moorings operating between 0 and 500 meters water depth. The sensors acquire data during ascent and descent. These transects allow to focus on the understanding of the impact of the Ligurian current on biological patterns. And, while the high-resolution in particular allows to address coupled sub-mesoscale processes, visiting the Boussole/Dyfamed site renders cross-comparisons of corresponding measurements (chlorophyll-a, backscattering, oxygen; performed by sensors on a fixed vs. moving platform) possible.
A typical glider trajectory in the Ligurian Sea. The glider starts in the outer part of the Bay of Villefranche-sur-mer which is situated close by Nice (French Riviera). It passes by the Boussole/Dyfamed mooring and directs towards Calvi (Corsica).
During the "Nice/Calvi" transect, the glider acquires data on various oceanic properties between sea surface and 1000 meters of water depth (ascent only). As an example of such a "medium-resolution" dataset the figure illustrates salinity measurements.
Also using salinity measurements as an example, this figure shows a "high-resolution" transect. The glider running from offshore Nice not further than to the Boussole/Dyfamed mooring acquires data during its ascent and descent between sea surface and 500 meters water depth.