Dataset: Suspended particles from in situ pumps on R/V Kilo Moana cruise KM1910 in June 2019

Sampling and analytical procedures:

Particulates were collected using in situ pumps (25, 45, 75, 100, 125, 150, 225, and 300 m ocean depth) aboard the RV Kilo Moana. Pump heads were loaded with an acid-washed 51um nitex mesh screen as a pre-filter followed by a combusted (4.5hrs 450 degrees C) 142mm GF75 (Advantec nominal pore size 0.3um). An adjacent pump head was loaded with a 52um Sefar filter. Additional 142mm GF75 filters were placed in cages and secured to the side of pumps during deployments and served as wet blanks for PC, POC, PIC, PN analysis. Filters were subsampled with a metal cork borer of known area, folded (active side in), and stored in clean (combusted) foil at -20 degrees C until analysis. The 0.3 to 51um size fraction samples analyzed at Princeton (subsample IDs “m1” and “m2”) and MBL labs (subsample ID “z”) were not acidified so PC and d13C represent total C; subsamples analyzed at WHOI for POC were acidified (subsample IDs “q” (small size fraction 0.3 to 51um) and “r” (large size fraction >51um). Subsamples were oven dried overnight at 55-60 degrees C then packed in 9x11 tin capsules for analysis on EA IRMS. Additional subsamples were analyzed for PIC at WHOI (subsample IDs “p” (small size fraction 0.3 to 52um) and “y” (large size fraction >52um)). PIC samples were stored frozen (-20C) on the ship and dried at 60C for 6-8h on shore, stored in 47mm petri dishes. Filters were analyzed roughly 2 months after collection following established procedures (Dong et al., 2019, Subhas et al., 2019).

Problem report:

Large particle (>51 micron) PIC data was not collected at 100m because that filter was allocated for other measurements.  Mass of N on subsample was too low for 15N measurement at 225 m and 300 m. Filter subsample “z” was only collected at one depth (25 m).