The rosette is one of the the water sampling devices used by the USGS Ocean Acidification Research team. It is a set of 24 sampling bottles called Niskin bottles that are connected to a frame that is lowered to the seafloor from the ship by a cable. The bottles remain open at the top and the bottom while being lowered to the desired depth beneath the sea surface.
Each Niskin bottle can be closed from the Healy to capture a water samples at different water depths. Once the rosette returns to the surface, it is placed on the ship so the scientists can collect the water from the bottles and preserve it for chemical analyses.
When the Rosette is back on board, the scientists carefully extract samples from the Niskin bottles and carry them to the laboratory for analysis. Water sampling done on this cruise will provide data at depth about the Arctic Ocean such as alkalinity, pCO2, carbonate, dissolved oxygen, dissolved inorganic carbon, pH, fluorescence, conductivity, and temperature.
Some of the water samples are preserved and stored for analysis back at the USGS Center for Coastal and Marine Research Laboratory in St. Petersburg, Florida – a long way for water from the Arctic Ocean to travel.