Particulate Organic and Inorganic Carbon Data Obtained on United State Coast Guard Cutter Healy (Cruise HLY-22-02), Western Arctic Ocean, 2022.

The US Coast Guard Cutter Healy completed a roundtrip research cruise (HLY-22-02) from Dutch Harbor, Alaska (AK) to the North Pole between September 4 to October 24, 2022. The northbound transect leg crossed the eastern shelf of the Chukchi Sea, the Canada Basin, and the Amerasian Basin, with the southbound leg crossing the Eurasian and Makaraov Basins, and across the western Chukchi Sea back through the Bering Strait to Dutch Harbor. The multi investigator cruise plan anticipated a total of 61 stations, covering several historic polar transects to allow for data comparison: Chukchi Ecosystem Observatory moorings (Station 0), the East Hannah Shoal transect (Stations 1-9) from the 2002-2004 Shelf Basins Interactions Program, the western route to the North Pole was previously sampled by the 1994 Arctic Ocean Section, and both routes to the North Pole were sampled during the 2015 GEOTRACES cruise (Ashjian & Grebmeier, 2023). Due to a variety of ship issues affecting deployments and multiple days of unfavorable ice and sea conditions, a total of 50 stations were completed. Of these, large volume pump sampling of water column particulates in the upper 500 m (meters) occurred at 16 stations. Depth-specific sampling of water column particulate matter within the upper 500 m was completed at 16 stations using four dual-head vertical McLane Research Labs., Inc. Water Transfer System Large Volume Pumps (WTS-LVPs). The pumps are programmed to a specified flow volume, rate, or time to pump 100’s -1000’s of liters of seawater across large diameter filters to collect particulate matter. On HLY-22-02, the pumps were deployed from the stern using the ship’s hydrowire. Each pump was assigned a specific sample depth associated with a major hydrographic feature and Arctic water mass as identified in previous expeditions (Bates & Mathis, 2009; Xiang & Lam, 2020): 75m (Polar Mixed Layer), 125 m (upper halocline), 225 m (lower halocline),and 500 m (Atlantic Deep Water). A pressure logger (from RBRGlobal) was attached to the 225 m pump to confirm the targeted depth was achieved in every deployment. Of the 16 stations, the last five stations had less than four pumps deployed due to shallow bottom depths.