Upstream Pathways of the Faroe Overflow (UFO)

WHOI cruises:

Following the deployment of the mooring array in late-summer 2024, a hydrographic/velocity survey was carried out on R/V Armstrong to investigate the far upstream sources of the Iceland-Faroe Slope Jet (IFSJ) (dataset linked below). The main goals of the survey were to (i) determine if/how the IFSJ is connected to the flow along the Jan Mayen Ridge, the Kolbeinsey Ridge, and the East Icelandic Current; (ii) confirm the existence of the southward flow along the Mohn Ridge implied by historical data; and (iii) verify that the Greenland Sea Gyre is the predominant source of the dense transport mode of the Faroe Bank Channel overflow (FBCO) rather than the Iceland Sea Gyre. Water samples for measuring oxygen, nutrients, CFC-12, and SF₆, which collectively can be used to identify water mass fingerprints and to compare our results to previous studies, were collected.

In 2025, after the mooring array is recovered, a second hydrographic/velocity survey will be conducted, this time covering the region from the array to the sill of the Faroe Bank Channel. This is meant to establish the connection between the IFSJ + Norwegian Sea Gyre (NSG) Rim, and the FBCO, including any modification of the dense water as it proceeds from the array to the overflow.

FAMRI cruises:

During the mooring deployment period, FAMRI will occupy standard hydrographic sections four times a year, which includes collection of nutrients. FAMRI’s new research vessel, R/V Jákup Sverri, has a hull-mounted ADCP which adds valuable velocity information. During UFO, additional hydrographic stations will be added to the northern section in the vicinity of the IFSJ for better resolution. FAMRI will also occupy another section adjacent to the joint mooring array on their mooring cruises to the Iceland-Faroe Ridge. Datasets linked below.

MFRI cruises:

Three times a year (winter, spring, summer) MFRI occupies standard hydrographic sections around Iceland. These sections were instrumental in the discovery and quantification of the NIJ, and were also valuable in documenting the IFSJ. During UFO, extra stations will be added to key sections north of Iceland, and an additional high-resolution transect will be occupied between the two zonal sections east of Iceland. Datasets linked *here*.