During the ArcticNet annual cruises of the research icebreaker CCGS Amundsen, characteristics of the near-surface atmosphere are monitored in conjunction with surface sea water properties to observe the relationship between the surface micro-climate and the air-sea exchange , with particular interest in CO2. Central to this integrated dataset is an eddy covariance system used to monitor fluxes of CO2, H2O, heat and momentum. The system continuously sampled the following variables at a rate of 10 Hz (instrument used to collect each variable is in parentheses, and approximate instrument height above surface is indicated): -3D wind velocity (Gill R3 and Gill Windmaster Pro ultra-sonic anemometer) - 15m -Sonic air temperature (Gill R3 and Gill Windmaster Pro ultra-sonic anemometer) - 15m -CO2 molar concentration (LI7500 open path gas analyzer) - 15m -H2O molar concentration (LI7500 open path gas analyzer) - 15m -CO2 mixing ratio (LI7000 integrated into a closed path system) - 15m -H2O mixing ratio (LI7000 integrated into a closed path system) - 15m -3D ship motion - angular rates and accelerations (MotionPak, Systron Donner) - 13m All instruments were mounted on a meteorological tower on the bow of the research icebreaker CCGS Amundsen.

Raw and post-processed precipitations were collected using a Thies Clima laser precipitation gauge. The instrument was mounted on the railing of the deck atop the bridge of the CCGS Amundsen. It should be noted that there was no good location to install the instrument, and wind eddies may have influenced the data.

During the ArcticNet annual cruises of the research icebreaker CCGS Amundsen, characteristics of the near-surface atmosphere are monitored in conjunction with surface sea water properties to observe the relationship between the surface micro-climate and the air-sea exchange , with particular interest in CO2. Central to this integrated dataset is an eddy covariance system used to monitor fluxes of CO2, H2O, heat and momentum. The system continuously sampled the following variables at a rate of 10 Hz (instrument used to collect each variable is in parentheses, and approximate instrument height above surface is indicated): -3D wind velocity (Gill WindMaster Pro ultra-sonic anemometer) - 15m -Sonic air temperature (Gill WindMaster Pro ultra-sonic anemometer) - 15m -CO2 molar concentration (LI7500 open path gas analyzer) - 15m -H2O molar concentration (LI7500 open path gas analyzer) - 15m -CO2 mixing ratio (LI7000 integrated into a closed path system) - 15m -H2O mixing ratio (LI7000 integrated into a closed path system) - 15m -3D ship motion - angular rates and accelerations (MotionPak, Systron Donner) - 13m All instruments were mounted on a meteorological tower on the bow of the research icebreaker CCGS Amundsen.

Sinking export of organic material was investigated during the fall of 2006, using free-drifting, short-term particle interceptor traps . The particle interceptor traps were deployed at 9 stations along a transect spanning between the North Water polynya (Baffin Bay) and the Beaufort Sea. The traps were deployed from the CCGS Amundsen at three depths below the euphotic zone (50, 100 and 150 m) for a period between 8 and 29 hours. The analyses on the sinking material included total chlorophyll a and phaopigments (fluorometric determination), particulate organic carbon and nitrogen, biogenic silica, cell composition and abundance and fecal pellet abundance.

Two video surveys were conducted in July 2016 at Disko Fan (South East Baffin Bay, Nunavut, Canada) using a Super Mohawk remotely operated vehicle (ROV) aboard CCGS Amundsen. The benthic environment was video-recorded and photographed using a high-definition camera (1Cam Alpha, Sub C Imaging, 24.1 megapixels), at a depth range of 888-941 m. Sites suitable for the deployment of box-cores and piston-cores were identified from the videos during the first survey, samples of corals, sponges and a zoanthid were collected (N= 13), and a video transect was conducted. Sea water was collected at several depth intervals from surface to near-bottom to determine calcium carbonate saturation.

The CTD data was obtained during the 2010 ArcticNet scientific cruise #1002a in collaboration with the industrial partner BP. The data were collected from August 15 to 25, 2010, aboard the CCGS Amundsen. There were 33 casts associated to 26 stations, located in the Beaufort Sea. The following parameters were measured: temperature, conductivity and pressure (with a Sea-Bird SBE-9plus), dissolved oxygen (Sea-Bird SBE-43), fluorescence (Seapoint chlorophyll fluorometer), CDOM (Wetlabs FL(RT)D), nitrate concentration (Satlantic MBARI-ISUS 5T), transmittance (Wetlabs C-Star transmissometer), light intensity (PAR; Biospherical Instruments QCP2300) and surface light intensity (sPAR; Biospherical Instruments QCP2200). Quality control procedures were applied to the data. Data are available on the Polar Data Catalogue and at the Marine Environmental Data Service (MEDS) of Fisheries and Oceans Canada.

A video-survey using a Super Mohawk remotely operated vehicle (ROV) was conducted in October 2015 at Inner Frobisher Bay, Nunavut. The benthic environment was video-recorded and opportunistically photographed using a high-definition camera (1Cam Alpha, Sub C Imaging, 24.1 megapixels), at a depth of ~59-139 m along a transect line 1.2 km long.

Free-drifting, short-term particle interceptor traps were deployed from the CCGS Amundsen on eight occasions between 23 September and 16 October 2005. The traps were deployed at two or three depths below the euphotic zone (from 25 to 150 m) for 8 to 20 h. The sinking material was analyzed for particulate inorganic carbon, particulate and dissolved organic carbon, biogenic and lithogenic silica and chlorophyll a concentrations. Phytoplankton abundance and composition, fecal pellet abundance and biovolume and bacterial abundances were also assessed for the sinking material. Water column samples, from depths between 10 and 150 m, were collected to quantify fecal pellets. Lastly, phytoplankton from the deep chlorophyll maximum depth was collected and their sinking velocity determined using settling columns.

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/​).

Coral samples were collected in Pond Inlet and Lancaster Sound in Baffin Bay using the CCGS Amundsen’s remotely operated vehicle (ROV). Samples from Agassiz trawl and box-core deployments were also kept as part of this study (11 stations). Samples were collected between 253 and 856 m. Specimens were subsampled aboard and frozen for determination of their carbon and nitrogen stable isotopic composition, as well as for lipids and fatty acids composition, as part of a study focusing on the trophic ecology of cold-water corals. Carbon and Nitrogen stable isotope analysis as well as lipids/fatty acids analysis were performed on tissue samples of soft corals at the Stable Isotopes Laboratory and Lipids Laboratory, Memorial University, respectively.