Suspended Organic Particle concentration and stable C and N isotopes from the Eastern Tropical North Pacific in April 2018 (R/V Roger Revelle RR1805) and October 2019 (R/V Kilo Moana KM1920)

Suspended Organic Particle Carbon and Nitrogen concentrations and stable C and N isotopes were obtained from the Eastern Tropical North Pacific on the R/V Revelle cruise RR1805 in April 2018 and the R/V Kilo Moana cruise KM1920 in October 2019. R/V Revelle cruise RR1805 sampled two stations in 2018: St P2 (16.9ºN 107ºW) and St P1 (20.3 °N 106.1°W). These two stations included an anoxic Oxygen Deficient Zone from 105-820 m for St P2 and 68-800 m for St P1. The R/V Kilo Moana cruise KM1920 sampled two stations in 2019: St P2 (16.9°N 107°W) and St P3 (21.8°N 109.9°W). These two stations included an anoxic Oxygen Deficient Zone from 110-820 m for St P2 and 160-650 m for St P3. St P3 is at the Northern Edge of the Oxygen Deficient Zone. St P2 is offshore in the core of the Oxygen Deficient Zone, and St P1 is on the continental slope.

During both cruises, water for bulk suspended particulate organic C and N analyses was obtained from Niskin bottles on a CTD rosette and vacuum-filtered it onto pre-combusted GF/F filters. Samples were wafted with HCl to remove carbonate and sent to the UC Davis Stable Isotope Facility (Davis, CA) for C and N analysis utilizing an elemental analyzer attached to an isotope ratio mass spectrometer.

The samples were obtained to determine whether organic matter concentrations increased and isotopic composition changed at the secondary chlorophyll maximum in the Oxygen Deficient Zone and at the zooplankton/forage fish vertical migration depth in the Oxygen Deficient Zone. St P2 and St P1 had a secondary chlorophyll maximum and St P3 did not.

Samples were collected and data were analyzed by Clara Fuchsman of Horn Point Laboratory, a part of the University of Maryland Center for Environmental Science.

本数据集包含2018年4月「雷维尔号」（R/V Revelle）RR1805航次与2019年10月「基洛莫阿纳号」（R/V Kilo Moana）KM1920航次在东热带北太平洋采集的悬浮有机颗粒碳、氮浓度及碳、氮稳定同位素数据。
2018年的RR1805航次共布设2个采样站位：P2站（16.9°N，107°W）与P1站（20.3°N，106.1°W）。其中P2站的缺氧含氧缺失带（Oxygen Deficient Zone，ODZ）分布于105~820米水深，P1站的缺氧含氧缺失带分布于68~800米水深。
2019年的KM1920航次布设2个采样站位：P2站（16.9°N，107°W）与P3站（21.8°N，109.9°W）。P2站的缺氧含氧缺失带分布于110~820米水深，P3站的缺氧含氧缺失带分布于160~650米水深。其中P3站位处于含氧缺失带的北缘，P2站位位于含氧缺失带核心区的远岸海域，P1站位则位于大陆坡区域。
两次航次的悬浮颗粒有机碳、氮总量分析水样均通过CTD采水器阵列（CTD rosette）上的尼斯金采水瓶（Niskin bottle）采集，经真空过滤后富集于预灼烧过的GF/F滤膜上。样品经盐酸熏蒸脱除碳酸盐后，送至加州大学戴维斯分校稳定同位素实验室（UC Davis Stable Isotope Facility，加利福尼亚州戴维斯），利用连接同位素比值质谱仪的元素分析仪开展碳、氮同位素分析。
本次采样旨在探明含氧缺失带内次级叶绿素最大值层以及浮游动物/饵料鱼类垂直迁移深度处的有机质浓度是否升高、同位素组成是否发生变化。其中P2站与P1站存在次级叶绿素最大值层，P3站则无此特征。
本数据集的样品采集与数据分析工作由美国马里兰大学环境科学中心霍恩角实验室（Horn Point Laboratory, University of Maryland Center for Environmental Science）的克拉拉·富克斯曼（Clara Fuchsman）完成。