The Canadian research icebreaker CCGS Amundsen is equipped with an underway ThermoSalinoGraph (TSG) system, which continuously records surface seawater temperature, salinity, fluorescence and sound velocity along the transit route. Quality Assurance/Quality Control (QAQC) data are available for the summer periods between 2005 and 2020, except in 2007, 2008 and 2012 where the system was faulty or the ship was in maintenance. The TSG data were corrected and controlled by comparing them to CTD-Rosette data and in situ measures when available. Outliers and suspicious measurements were removed from the dataset. Variables are provided every 7 minutes. Research programs participating in the Amundsen expeditions between 2005 and 2020 include, ArcticNet, CFL, Geotraces, Malina, IOL and BP, BREA, Weston, Netcare, JAMSTEC, Statoil and iBO, GreenEdge, BAYSYS, Sentinel Nord (BriGHT, BOND), DFO ROV vulnerable marine ecosystem, and the Kitikmeot marine Ecosystem.

Field observations were made in the southern Beaufort Sea and the Amundsen Gulf as part of CASES 2003 expedition. Samples were collected during the first two legs of the expedition from 13 September to 14 October 2003 (open water) and from 15 October to 25 November 2003 (newly formed sea ice) onboard the Canadian icebreaker CCGS Amundsen. Temperature and salinity profiles were obtained using a SeaBird 911 Conductivity¿Temperature¿Depth (CTD) probe. Nutrient concentrations (nitrate plus nitrite, phosphate, and silicate) were determined on fresh samples (within 1 h of sampling) using standard colorimetric methodologies adapted for use on an Auto-Analyzer 3 (Bran þ Luebbe). A RAMSES ASC scalar hyperspectral irradiance sensor (TriOS) was mounted on the flight bridge to measure downwelling irradiance with 1 nm intervals during the day. A total of 50 and 102 discrete water samples were collected over the euphotic zone at 13 and 20 stations for legs 1 and 2, respectively for fluorometrically chlorophyll a measurements and absorption analysis of phytoplankton, non-algal particules (NAP) and colored dissolved organic matter (CDOM). Water samples (preserved in acidic Lugol solution) were enumerated and identified to the lowest possible taxonomic rank using an inverted microscope. Concentrations of chlorophyll a and chlorophyll b were obtained by HPLC measurements and these two pigments were used for the calculation of the ratios of chl b to chl a.

Microplastics pollution has been found across the globe, but with limited information from the polar regions. Although there is evidence of microplastics in the Arctic and Antarctic, little is understood about the sources, fate and extent of contamination. We collected samples and will quantify the amount and identify the types of microplastics in snow (as a surrogate for air), water, sediments and zooplankton sampled from the CCGS Amundsen in and around the Hudson Bay and/or the central and eastern Canadian Archipelago. In addition, we will answer questions about sources and fate using two types of information. First, we will collaborate with an Indigenous community to quantify and type plastic along their shoreline. Second, we will examine patterns of microplastics contamination and compare them with land-use patterns and water and air circulation. Based on previous studies, and our preliminary findings, we believe that microplastics will be present in Arctic samples, but a detailed study will help us better understand how ubiquitous microplastics are, from where they are derived, and how they are preserved or degraded. Microplastics in the Arctic raise concerns about impacts to wildlife and local communities that rely on food from the sea. Results from this study will inform future experiments that answer questions related to such impacts.

The LADCP data was obtained during the years 2009, 2010, 2011, 2014, 2015, 2017, 2018 and 2019 aboard the CCGS Amundsen. The following parameters were measured: DEPTH (Depth Below Sea Surface [m]), EWCT (East (true) Component of Current [m/s]), NSCT (North (true) Component of Current [m/s]), and ERRV (Error Velocity [m/s]). This archives contain the final absolute velocity profile for each cast. Quality control procedures are applied to the data. Data are available on Polar Data Catalogue under the format .lad (one cast by file).

Data were mainly collected from the CCGS Amundsen (2015 to 2019) and from the William-Kennedy (2019). An Agassiz trawl (1.5 m width × 0.7 m height, cod end of 0.5 cm mesh size) was towed on the seabed at a speed of 1.5-2 knots for 3 to 5 minutes to survey epibenthic species diversity, abundance, and biomass. Retrieved samples were washed with seawater in a sieve (2 mm mesh), and organisms were sorted and identified to the lowest taxonomical level possible. Each taxon was counted, and biomass was measured. A box corer was deployed to quantitatively sample diversity, abundance, and biomass of endobenthic organisms (macrobenthos > 0.5 mm). After retrieval of the box corer, a subsample of 0.125 m2 area and 12-15 cm depth was collected and passed through a 0.5 mm mesh sieve to separate sediment from endofauna. Organisms were immediately preserved in a 4% buffered formaldehyde solution for further taxonomical identification in the laboratory.

Microplastics pollution has been found across the globe, but with limited information from the polar regions. Although there is evidence of microplastics in the Arctic and Antarctic, little is understood about the sources, fate and extent of contamination. We collected samples and will quantify the amount and identify the types of microplastics in snow, ice, water, sediments and zooplankton sampled from the CCGS Amundsen in and around the Hudson Bay and/or the central and eastern Canadian Archipelago. In addition, we will answer questions about sources and fate using two types of information. We will examine patterns of microplastics contamination and compare them with land-use patterns and water and air circulation. Based on previous studies, and our preliminary findings, we believe that microplastics will be present in Arctic samples, but a detailed study will help us better understand how ubiquitous microplastics are, from where they are derived, and how they are preserved or degraded. Microplastics in the Arctic raise concerns about impacts to wildlife and local communities that rely on food from the sea. Results from this study will inform future experiments that answer questions related to such impacts.

Datasets were collected and processed by the Ocean Mapping Group, University of New Brunswick. Accoustic data was generated from the multibeam Kongsberg Simrad EM302 multibeam sonar system onboard the CCGS Amundsen during ArcticNet Cruises. This bathymetric data subset covers the Greenland Economic Exclusive Zone (EEZ), i.e. outside of the 12 nm territorial sea extent and within the 200 nm EZZ, from 2005 to 2011 and 2013. The datasets consist of high-resolution bathymetry and acoustic backscatter imagery collected 24 hours a day, whenever the ship was in transit or had dedicated survey time. Standard collection settings used dual-ping, FM pulse, auto depth mode, angular coverage of +/- 60 degrees and high-density equidistant beamforming. SIS was used to collect the data, while near realtime cleaning of data outliers was done using the Ocean Mapping Group's Swathed toolkit after conversion to OMG binary format. IMU data was parsed by the SIS software from a POSMv 320 v.4. RTG GPS data from the CNav GPS was used to correct and improve the position output from the POSMv. Soundspeed information was either from CTD Rosette casts, MVP300 data or simulated from the World Ocean Atlas 2001 database. Data were gridded at a resolution of 10 metres. Grid files available are in ESRI grid format (.flt and .hdr files zipped for each mapsheet for the data from 2005 to 2011, and .asc files for the data of 2013). Futher information on data processing and on the Ocean Mapping Group activities are online at http://www.omg.unb.ca/Projects/Arctic/

The dataset is composed of raw files (.raw) recorded with a SIMRAD EK60 three-frequency (38, 120, 200 kHz) split-beam echosounder that was operated continuously during the ArcticNet cruise aboard the CCGS Amundsen from 2006 to 2016 (no data were collected in 2012 due to the CCGS Amundsen being in dry dock). All three 7° transducers were hull-mounted and calibrated prior to departure. The acoustic signal was recorded continuously on a PC using ER60 software version 2.0.0. Ping rate varied from 1 to 2 seconds depending on maximum depth, and the pulse length was set at 1.024 milliseconds. The files can be read with the open source programming software R, other proprietary programming software like MATLAB or with specific proprietary software for hydro-acoustic analysis such as Echoview (https://www.echoview.com/​).

Environment Canada installed a meteorological system on the Voluntary Observing Ship (VOS) scheme part of the CCGS Amundsen. The system is composed of a Digital Barometer (Vaisala PTB-210), an R.M Anemometer (Young 05103) and a Humidity-Temperature Meteorological sensor (Rotronic MP101). The system continuously recorded Atmospheric pressure, Wind Speed and Direction, Air temperature and Humidity every 4 seconds for the CCGS Amundsen expeditions between 2004 and 2017. No data was collected in 2012 since the vessel was undergoing maintenance (dry docks). The true wind was directly calculated by the system using the ship's gyrocompass, the recorded apparent wind and Global Positioning System (GPS) data (speed and track of the ship from POS-MV and C-NAV Differential Global Navigation Satellite System (DGNSS) Precise Point positioning systems). Then the AVOS system averaged the data at 10 minute or hourly intervals. Outliers and suspicious measurements were removed from the dataset and the resulting controlled data are provided at 10 minute or hourly intervals for each day of the expeditions. Research programs participating in the Amundsen expeditions between 2004 and 2017 include CASES, ArcticNet, CFL, Geotraces, Malina, IOL and BP, BREA, Weston, Netcare, JAMSTEC, Statoil and iBO and GreenEdge.

The Canadian research icebreaker CCGS Amundsen is equipped with multi-plankton sampler system called Hydrobios. The MultiNet Type Maxi, part of the system, is used for vertical collections. An integrated CTD unit is also integrated to the system and allows recording of the sampled water characteristics. This dataset is composed of CTD profiles and specific data for the volume of water going through the nets during their operation. The Hydrobios was deployed during the Amundsen scientific expeditions in the summer and fall between 2003 and 2019 with the exception of 2004, 2005, 2009, 2011 and 2012, where no data is available. The integrated CTD sensors are from the Hydrobios company itself. The Hydrobios-CTD data were corrected and controlled by comparing them to CTD-Rosette data when available. Outliers and suspicious measurements were removed from the dataset. Variables are provided for every 2 decibars (dbar) between the maximum and minimum pressure recorded for each cast. Research programs participating in the Amundsen expeditions between 2003 and 2016 include CASES, ArcticNet, CFL, Geotraces, Malina, IOL and BP, BREA, Weston, Netcare, JAMSTEC, Statoil, iBO, GreenEdge, BAYSYS and DFO programs. In-situ data belong to and are under the responsibility of the leading Nets scientists while physical and chemical data from the sensors are part of the Amundsen core data collection.