SBI: 2003 Helo Survey ISUS Nitrate Concentrations, Temperature, Salinity, and Density. Version 1.0

As part of the Shelf-Basin Interactions (SBI) project, early spring sampling was performed in the eastern area of the SBI study area using aircraft. Flights began on 1 April 2003 and finished on 15 April. During this time, we sampled 42 sites (49 Conductivity Temperature Depth (CTD) casts) on a series of 5 transect lines which bracketed and were parallel to the SBI current meter mooring line located at 152 W longitude. Stations were about 10 km apart along each transect line. A map of the achieved sampling sites is available (file: Sw3loc4a.pdf) and station locations, sampling dates and times are found in the file, Sw3vit-4.csv. At sites 10 through 49, a Seabird CTD (SBE-25) and Satlantic In-Situ Ultraviolet Spectrophotometer (ISUS) nitrate analyzer with a water sampling bottle was deployed through an 8 inch hole augured through the pack-ice. Continuous profiles of pressure, temperature, salinity, and ISUS-sensed nitrate concentrations were made from the ice hole to either the sediment surface or to about 390 m. The ISUS was not used at CTD casts 1 through 9. CTD data were processed with Seabird software (Seasoft) and the data binned into 0.5 dbar layers. All basic CTD data are contained in another dataset as well as the nutrient data collected from the water sampling bottles. The ISUS samples at a relatively slow rate (3.5 Hz), and even though repeated vertical profiles were collected at each site, not all pressure bins contained ISUS measurements. Data herein include basic CTD data as well as the ISUS data (in its respective bin) converted to nitrate concentration, and the continuous ISUS nitrate profiles constructed by linearly interpolating binned data between two vertically adjacent ISUS averages. A complete description of the evaluation procedure for these ISUS data is being prepared for publication, so data herein are considered to be in draft form. The data are in csv format.

作为陆架-盆地相互作用（Shelf-Basin Interactions, SBI）项目的一部分，本研究依托航空平台于2003年4月初在SBI研究区域东部海域开展早春采样作业。飞行任务于2003年4月1日启动，至4月15日结束。
本次采样期间，研究团队在5条断面线上共布设42个采样站点，完成49站温盐深（Conductivity Temperature Depth, CTD）剖面测量；所有断面均环绕并平行于位于西经152°的SBI海流计锚系测线，各断面上的站点间距约为10千米。
已完成的采样站点分布图可查阅文件Sw3loc4a.pdf，站点位置、采样日期与时间信息则存储于文件Sw3vit-4.csv中。
在第10至第49号站点，研究人员通过在浮冰上钻取的8英寸孔洞，部署了SeaBird公司生产的CTD（SBE-25型）以及Satlantic公司生产的原位紫外分光光度计（In-Situ Ultraviolet Spectrophotometer, ISUS）硝酸盐分析仪并配套取水样瓶。从冰孔至沉积物表层或约390米深度处，连续采集了压力、温度、盐度以及ISUS检测的硝酸盐浓度剖面数据。
第1至第9号CTD剖面站位未启用ISUS设备。
CTD数据采用SeaBird公司的Seasoft软件进行处理，并被划分为0.5分巴（dbar）的分层数据。
所有基础CTD数据以及从取水样瓶中获取的营养盐数据均存储于另一数据集当中。
ISUS设备的采样速率相对较低（3.5赫兹），尽管每个站点均开展了多次垂直剖面采样，但并非所有压力分层都包含ISUS检测数据。
本数据集包含基础CTD数据、转换为硝酸盐浓度的ISUS分层数据，以及通过对两个垂直相邻的ISUS平均数据进行线性插值得到的连续ISUS硝酸盐浓度剖面。
针对这些ISUS数据的完整评估流程说明正准备发表，因此本数据集的数据暂处于草稿版本状态。
本次发布的数据采用CSV格式存储。