Oceanographic observations (CTD and CDOM fluorescence) in the eastern Canadian Arctic Archipelago, northern Baffin Bay and Nares Strait in August-September 2024

Data are Conductivity-Temperature-Depth (CTD) and Colored Dissolved Organic Matter (CDOM) fluorescence profiles collected in August-September 2024 from the Canadian Coast Guard icebreakers Des Groseilliers and Amundsen in the eastern Canadian Arctic Archipelago in Nansen Sound, Eureka Sound, Norwegian Bay, Jones Sound, and Nares Strait and the northern Baffin Bay. Data file is in ASCII format.

The CTD observations from CCGS Des Groseilliers were carried out with a Sea-Bird Scientific SBE-19plus CTD that was accurate to ±0.005°C and ±0.0005 S m–1. The CTD observations aboard CCGS Amundsen were taken using a Sea-Bird 9plus CTD that was accurate to ±0.001°C and ± 0.0003 S m–1. CTDs were calibrated prior to the expeditions. We used practical salinity calculated directly from the conductivity and temperature of seawater as defined by Practical Salinity Scale 1978 (Lewis, 1980). All CTD casts were taken through the full water column (CCGS Amundsen) or to a maximum depth of 520 m (CCGS Des Groseilliers). All data was 1-meter binned.

The CTDs aboard CCGSs Des Groseilliers and Amundsen were outfitted with a Wet Labs ECO fluorometer for measuring CDOM fluorescence for EX/EM = 370/460 nm. The CDOM sensor sensitivity is 0.09 parts per billion (ppb). The CDOM sensor aboard CCGS Des Groseilliers was calibrated prior to the expedition. However, the resulting measurements were not post-calibrated against discrete samples. The CDOM sensor aboard CCGS Amundsen was not calibrated prior to the expedition resulting in data offset relative to that of CCGS Des Groseilliers. For overlapping, the CDOM profiles taken from CCGS Amundsen were adjusted by 1.77 mg m–3 assuming that for depths >500 m, the CDOM values at the mouths of Nansen Sound are consistent with that at the mouth of Nares Strait. CDOM profiles were averaged with a 7-meter moving window.

Our data shows that CDOM fluorescence assessed by optical sensors is a powerful tool for tracing water mass origins and circulation patterns. CDOM fluorescence can act as a tracer of Pacific water revealing how Pacific water transfers within the Canada Basin, flows through the Canadian Arctic Archipelago and Nares Strait and interacts with water of the West Greenland current in the northern Baffin Bay.

This data set supplements paper "Using Colored Dissolved Organic Matter (CDOM) fluorescence to trace the Pacific-derived water in the Eastern Canadian Arctic" by Igor A. Dmitrenko, Colin A. Stedmon, David G. Babb, Bert Rudels, Sergei A. Kirillov, Jens Ehn, Tonya Burgers, and Dorthe Dahl-Jensen accepted for publication in Scientific Reports, https://doi.org/10.1038/s41598-026-38848-2

本数据集包含2024年8-9月于加拿大北极群岛东部海域（包括南森湾、尤里卡湾、挪威湾、琼斯湾、内尔斯海峡以及巴芬湾北部），由加拿大海岸警卫队（Canadian Coast Guard, CCGS）破冰船“德·格罗塞利耶号”与“阿蒙森号”采集的电导率-温度-深度（Conductivity-Temperature-Depth, CTD）剖面数据与有色溶解有机物（Colored Dissolved Organic Matter, CDOM）荧光剖面数据。数据文件格式为ASCII。

“德·格罗塞利耶号”搭载的CTD观测由Sea-Bird Scientific SBE-19plus型CTD完成，其测量精度为±0.005℃与±0.0005 S·m⁻¹；“阿蒙森号”搭载的CTD观测则采用Sea-Bird 9plus型CTD，测量精度为±0.001℃与±0.0003 S·m⁻¹。所有CTD设备均在航次前完成校准。本数据集采用1978年实用盐度标度（Practical Salinity Scale 1978, Lewis, 1980）中定义的、直接由海水电导率与温度计算得到的实用盐度。所有CTD站位均实现全水柱采样（“阿蒙森号”），或最大采样深度达520米（“德·格罗塞利耶号”）。所有数据均以1米为间隔进行分箱处理。

“德·格罗塞利耶号”与“阿蒙森号”搭载的CTD均配备Wet Labs ECO型荧光计，用于测量激发/发射波长（EX/EM）为370/460 nm的CDOM荧光信号。该CDOM传感器的灵敏度为0.09十亿分比（parts per billion, ppb）。“德·格罗塞利耶号”搭载的CDOM传感器已在航次前完成校准，但所得测量数据未通过离散样本进行后校准。“阿蒙森号”搭载的CDOM传感器未在航次前校准，导致其数据与“德·格罗塞利耶号”的数据存在系统偏差。针对重叠观测区域，假设深度大于500米时南森湾口的CDOM值与内尔斯海峡口的CDOM值一致，我们将“阿蒙森号”获取的CDOM剖面数据统一校正了1.77 mg·m⁻³。所有CDOM剖面数据均采用7米移动窗口进行平均处理。

本数据集的分析结果表明，光学传感器探测的CDOM荧光是追踪水团起源与环流模式的有效工具。CDOM荧光可作为太平洋水团的示踪剂，用于揭示太平洋水团在加拿大海盆内的输运过程、穿越加拿大北极群岛与内尔斯海峡的路径，以及其在巴芬湾北部与西格陵兰洋流团的相互作用机制。

本数据集为已被《Scientific Reports》接收待刊的论文"Using Colored Dissolved Organic Matter (CDOM) fluorescence to trace the Pacific-derived water in the Eastern Canadian Arctic"（作者：Igor A. Dmitrenko、Colin A. Stedmon、David G. Babb、Bert Rudels、Sergei A. Kirillov、Jens Ehn、Tonya Burgers、Dorthe Dahl-Jensen）提供数据支撑，论文DOI：https://doi.org/10.1038/s41598-026-38848-2