Nitrate d15N and d18O from Niskin bottle samples collected on Leg 2 (Hilo, HI to Papeete, French Polynesia) of the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15, RR1815) on R/V Roger Revelle from October to November 2018

These data include nitrate δ15N and δ18O along US GEOTRACES GP15, a meridional transect at ~152°W in the Pacific Ocean. The Pacific hosts significant rates of all the fluxes that are relevant to the global N cycle: the N budget fluxes (those that either generate or consume fixed N; N2 fixation and denitrification) as well as the N fluxes from the internal N cycle (those that generate or consume nitrate but leave the fixed N pool unaltered; nitrate regeneration and assimilation). The nitrate δ15N and δ18O provide a useful tool to separate and possibly quantify the overlapping impacts of all these co-occurring processes.

GP15 was a 60-day research cruise that took place in 2018 along a transect form Alaska to Tahiti at 152° W on board of the R/V Revelle. The cruise was completed in two legs (RR1814 and RR1815), which started on the 18th of September and on the 24th of October 2018, respectively. This dataset includes data from Leg 2 (RR1815). Leg 1 data (RR1814) are provided in a separate, related dataset.

本数据集涵盖沿美国GEOTRACES GP15断面采集的硝酸盐δ¹⁵N与δ¹⁸O实测数据，该断面为太平洋海域约152°W处的经向断面。太平洋存在与全球氮循环密切相关的各类核心氮通量过程：包括氮收支通量（即产生或消耗固定态氮的过程，如固氮作用与反硝化作用），以及内部氮循环通量（即仅生成或消耗硝酸盐但不改变固定态氮库总量的过程，如硝酸盐再生与同化作用）。硝酸盐δ¹⁵N与δ¹⁸O是区分并可定量估算上述多过程叠加影响的有效工具。
GP15对应的2018年科考航次为期60天，搭载于“雷维尔号”（R/V Revelle）科考船，沿152°W经向断面从阿拉斯加航行至塔希提岛。本次航次分为两个航段（RR1814与RR1815），分别于2018年9月18日和10月24日启航。本数据集仅包含第二航段（RR1815）的观测数据，第一航段（RR1814）的相关数据已收录于另一独立关联数据集。