| Summary: | We present concentrations of total particulate carbon (PC), carbonate (PIC), total particulate nitrogen (PN), δ¹³C and δ¹âµN of suspended particles along a North Pacific transect. In the upper 400 m, suspended PIC to particulate organic carbon (POC) ratios generally follow published sinking PIC/POC ratios. Below 600 m, suspended PIC/POC become significantly lower than sinking PIC/POC, likely indicating PIC dissolution within the suspended load. In three out of the five stations, suspended PN δ¹âµN increase with depth from the euphotic zone to the thermocline, consistent with previous observations in many ocean regions (e.g.,BATS and HOT). However, in the other two stations where phytoplankton blooms were encountered, high suspended PN δ¹âµN (up to 12‰) were observed in the euphotic zone, which was likely caused by the export of low-δ¹âµN PN during the phytoplankton blooms. Average C_(org) : N ratio of suspended particles along the transect is 5.1 ± 0.2, with the value in the subtropical gyre (5.8 ± 0.3) slightly higher than the subarctic gyre (4.6 ± 0.2). © 2021 Association for the Sciences of Limnology and Oceanography. Issue Online: 17 January 2022; Version of Record online: 26 November 2021; Manuscript accepted: 09 November 2021; Manuscript revised: 07 November 2021; Manuscript received: 16 March 2021. This work was supported by NSF Ocean Acidification grants (OCE1220600 and OCE1220302), Grantham Foundation and Simons Foundation (Grant 497534). The authors would like to thank the editor and reviewer for their helpful comments on an earlier version of our manuscript. They would also like to thank Mong Sin Christine Wu for her help in putting together Fig. 6a; Fenfang Wu and Nick E. Rollins for their help with EA analysis; Nicholas Hawco for his help in plotting the NASA satellite chlorophyll data; Nathan Kemnitz, Yi Hou, Abby Lunstrum, and the captain and crews on Kilo Moana for their assistance at sea. Conflict of Interest: None declared. Supplemental Material - ...
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