P02: Guam to San Diego

Overview

GO-SHIP P02 reoccupied the 30°N zonal transect across the full width of the North Pacific aboard the R/V Roger Revelle in two legs: Leg 1 (April 30 to June 10, 2022) from Guam to Honolulu under Chief Scientist Alison Macdonald and Co-Chief Scientist Shuwen Tan, and Leg 2 (June 13 to July 16, 2022) from Honolulu to San Diego under Chief Scientist Andreas Thurnherr. With more than 80 days at sea, it was the first full-scale Bio-GO-SHIP section, adding plankton genomics and gene expression, inline flow cytometry, particle chemistry, particle size, and pigment composition to the core GO-SHIP measurements.

Operations

Departure from Guam slipped to Saturday, April 30, while last-minute shipments were still arriving, and the science party used the wait to bring their equipment to peak operating condition. After a test cast and the first station, Leg 1 worked out of the Philippine Basin, across the Kuroshio Current and the subtropical mode waters of the western North Pacific, over one of the deepest trenches on the planet, and past the Izu-Ogasawara Ridge, before crossing the International Date Line at the end of May and heading east to Honolulu. Leg 2 transited over the Cretaceous-age volcanic Musician Seamounts to its first CTD station and continued along 30°N toward the California coast.

Scientific highlights

Beyond full-depth CTD/rosette profiles, LADCP velocity, and transient tracer (CFC) measurements, the cruise deployed a steady stream of GO-BGC biogeochemical Argo floats, each adopted and named by a school class, including Chelsea at Sea, Wolfie, Aggie, Minnie Paul, Bulldog Bait, Elgin Eagle, and Águila dorada on Leg 1, and Mysterious Blue, Baker Bio Bobber (30°N, 145°W), and Climate Buster (30°N, 131°W) on Leg 2. The last GO-BGC float of the section, Rambler Express, went in on a chilly July 9 morning at 31°45’N, 119°48’W, just off the coast of San Diego.

Fun facts

The ship had to reposition to avoid a large container ship before launching EYES, the final Argo float of Leg 1; the CFC team ran 10 pm to 10 am shifts; Bill the crocodile spent a day shadowing the Co-Chief Scientist; Duke Moosington II, a stuffed moose, rode along with his human companion; the Leg 2 crew spotted a white-tip shark; and, as on most cruises, food and meals structured the day and dominated conversation.