As part of the annual Fram Strait 2025 cruise (27 July – 14 August 2025) conducted by the Norwegian Polar Institute (NPI), the science team from the UK’s National Oceanography Centre deployed a new suite of autonomous Lab-on-Chip (LoC) sensors on long-term moorings in the East Greenland Current. These compact instruments measure pH, total alkalinity, nitrate and phosphate directly in the ocean, at high resolution and over many months.
Fram Strait is the one of the two main pathways where Arctic waters flow into the Nordic Seas and the Subpolar North Atlantic –with the Davis Strait on the west side of Greenland being the other main one. These Arctic waters carry a unique chemical “fingerprint” — rich in phosphate relative to nitrogen and already strongly affected by ocean acidification in the Arctic Ocean due to disappearing sea ice and freshening surface waters. While the NPI has monitored the Arctic freshwater, sea ice and returning Atlantic Water in the East Greenland Current via the Fram Strait Arctic Outflow Observatory since the 1990s, biogeochemical properties have only been measured in late summer through the water sampling programme implemented during their annual cruises since 2010. Tracking biogeochemical properties helps us understand not only what is happening in the Arctic, but also how it influences ecosystems and carbon cycling further south.
By combining carbonate chemistry and nutrient measurements in this remote gateway, the newly installed LoC sensors will provide year-round data that has never been captured before. These observations will improve estimates of Arctic nutrient and carbon exports, support international ocean acidification monitoring, and demonstrate how UK-developed autonomous technology can extend our reach in challenging environments.
