Surface water changes during transit from North Pole to Fram Strait

• Main Authors: Rutgers van der Loeff, Michiel, Casacuberta, Núria, Wefing, Anne-Marie, Laukert, Georgi, Bauch, D., Paffrath, Ronja, Provost, Christine, Karcher, Michael, Meyer, Hanno, Schaffer, Janin, Rabe, Benjamin
• Format: Conference Object
• Language: unknown
• Published: 2019
• Subjects: Greenland; North Pole; Pacific; East Greenland; east greenland current; Fram Strait; Sea ice
• Online Access: https://epic.awi.de/id/eprint/50416/; https://hdl.handle.net/10013/epic.c9ffe526-069a-460c-a2b0-bf6e53bee67e

Ice drift recorded by ice buoys show a relatively direct pathway of ice from the North Pole to Fram Strait. An ice tethered buoy deployed in 2015 during GEOTRACES section GN04 at 89°N was recovered in August 2016 at 76°43N in Fram Strait during GEOTRACES section GN05. Does the surface water follow a similar pathway? Tracer data collected during these two expeditions are used to investigate to what extent the water in the East Greenland Current (EGC) can be considered a downstream extension of the Transpolar Drift (TPD) at the North Pole. The reduction of 228Ra activities and 129I/236U ratios in the EGC compared to the TPD can be explained either by a much longer (order 3-4 years) travel time than suggested by the ice drift, or by admixture of surface waters from other, presumably Pacific sources. The pathways followed by surface water in a coupled sea-ice-ocean model suggest that the transit of surface water is indeed much more erratic and time consuming than the transit of ice. We will discuss whether N/P ratios or Nd isotopes give evidence for a change in the contribution of Pacific waters.