April 19-20: Successful Completion of the Pioneer 21 Cruise

The R/V Neil Armstrong neared Woods Hole after a successful Pioneer 21 Leg 2 expedition, scheduled to arrive Sunday morning at 09:00. Over the course of the cruise, the science and engineering teams completed all primary objectives, advancing OOI’s coastal ocean observing efforts.

In the final days at sea, the team completed a fourth transect along the LTER line, conducting CTD casts at the L10, L8, L6, and L4 stations. These additional observations provided valuable data to help the LTER team identify the location of the shelf break front ahead of their upcoming cruise.

The expedition also included an ROV dive to assess the SEPM-1 mooring anchor. The dive located the anchor and associated mooring components, providing critical information for planning future recovery operations. The anchor was left in a stable condition, and the dive offered new insights that will guide next steps for retrieving equipment in future missions.

Throughout the cruise, the team completed all planned mooring deployments and recoveries, along with CTD surveys, ADCP mapping, and biological sampling activities led by guest researchers from the University of North Carolina and East Carolina University. Favorable weather and strong collaboration among the ship’s crew, deck team, and science party ensured smooth and efficient operations.

Leg 2 of the Pioneer 21 deployment was notable for the strong teamwork and adaptability of the participants, including several individuals on their first OOI cruise. Every team member contributed to maintaining a safe, productive, and successful expedition.

As the R/V Neil Armstrong returned home, the Pioneer 21 Leg 2 team celebrated a cruise marked by excellent execution, valuable data collection, and new opportunities to further enhance OOI’s long-term ocean observing capabilities.

(c): Croy Carlin, WHOI