Despite Weather, Irminger 9 Met Objectives

The R/V Neil Armstrong departed Woods Hole, Mass., on June 20. Under the direction of Chief Scientist Sheri N. White of Woods Hole Oceanographic Institution (WHOI), the 14-member science party headed to OOI’s Global Irminger Sea Array for the ninth time to recover and deploy moorings and gliders and carry out scientific sampling. Nearly a month later, the ship and science party pulled into the port of Reykjavik, Iceland, on July 16^th, having accomplished all of its objectives.

“The Irminger Sea can be a challenging environment to work in. Storms with high winds and seas regularly move through the area, and these conditions can limit our mooring recovery and deployment operations,” said Chief Scientist Sheri N. White. “We were lucky to have relatively good weather conditions during our cruise, and adjusted our schedule when needed when storms passed through.  Thanks to an excellent team – the ship’s crew and shipboard science technicians, the mooring operations team, and OOI and OSNAP teams – we able to accomplish all of our goals.  My huge thanks to everyone on the ship and all of our shore-side support for all of their efforts.”

In addition to ten OOI personnel, the team was rounded out by three members from OSNAP (Overturning in the Subpolar North Atlantic Program) and a marine mammal observer from the National Oceanic and Atmospheric Administration.

For OOI, the team successfully recovered and deployed a Surface Mooring, Hybrid Profiler Mooring, and two Flanking Moorings, and deployed two new Irminger Sea gliders. For OSNAP, the team recovered and deployed four new moorings, replacing those originally deployed in the Summer 2020. The team also conducted CTD casts with salinity, oxygen, carbon, nutrient and chlorophyll water sampling. These sampling measurements are used for instrument validation and to further characterize the region of the moored array.

Why the Irminger Sea?

The Global Irminger Sea Array is off the southeast tip of Greenland, close to 39°W, 60°N. Data from this location are improving understanding of the impact of natural and climate variability in the region. The location experiences strong air-sea interaction and wintertime water mass formation that supports the global thermohaline (a.k.a. meridional overturning circulation – MOC). In recent years, a freshening of the water column has been observed.

The combination of the moored array and the gliders in the Irminger Sea enables investigation into the role of ocean processes at mesoscale and sub-mesoscale horizontal length scales through observations that sample the full water column, from the sea floor to the sea surface. The Surface Mooring provides a unique time-history of observations of surface meteorology and air-sea fluxes.

A Look at Life at Sea

The following and in the sidebar to the right is an assortment of activities onboard the Armstrong during the month of July.  Other images and stories can be found here.

Whale sightings: Marine mammal observer Peter Duley spent many hours on deck looking for marine mammals. He observed Humpback, Beaked, Sei, and Fin whales, as well as orcas, harbor porpoise and common dolphins. Credit: Sheri N. White © WHOI.

Pod came to visit: A pod of pilot whales on a foggy day in the Irminger Sea. Credit: Peter Duley, NOAA.

Glider missions: Gliders have two missions at the Irminger Sea Array. They travel around the triangular array to collect data (temperature, salinity, fluorescence and dissolved oxygen) in between the moorings. And, they pass the data from the subsurface mooring to shore. When they come to the surface, they send their data and the subsurface mooring data back to shore via satellite. Credit: Sawyer Newman©WHOI.