The Atlantic meridional transect is the long north–south section that research vessels run between Europe and the Southern Ocean, crossing every major surface water type in one voyage. Between 2002 and 2007 a LIF LiDAR rode several of these passages, including legs aboard R/V Akademik Ioffe, measuring chlorophyll a, CDOM and suspended matter in the open ocean far from any coast.
These are the clearest waters in the archive: oligotrophic Case-1 ocean with chlorophyll a typically between 0.08 and 0.2 µg/L, the regime low-power ultraviolet fluorescence LiDAR was originally designed to read at long sensing distance. Stations are spaced across thousands of kilometres rather than packed along a coast, a deliberately sparse sampling of basin-scale gradients, from the equatorial Atlantic north to the Labrador Sea and south toward the Drake Passage, and the deep-water heritage behind the company’s coastal and inland work.