A benthic survey using a Super Mohawk remotely operated vehicle (ROV) was conducted in July 2017 at Disko Fan, SE Baffin Bay. The benthic environment was video-recorded and opportunistically photographed using a high-definition camera (1Cam Alpha, Sub C Imaging, 24.1 megapixels), at a water depth of ~930 m. An experimental frame deployed in 2016 was recovered during this ROV dive, but no other collections took place at this site during this dive.

During the ArcticNet annual cruises of the research icebreaker CCGS Amundsen, characteristics of the near-surface atmosphere (basic meteorological elements, incident radiation, CO2 concentration) are monitored in conjunction with surface sea water properties (temperature, salinity, dissolved CO2 and O2) to observe the relationship between the surface micro-climate and the air-sea exchange, with particular interest in CO2. As part of this integrated dataset, the following radiation variables were recorded at 1 minute intervals (instrument used to collect each variable is in parentheses): incoming shortwave radiation (Eppley pyranometer, model PSP); incoming longwave radiation (Eppley pyrgeometer, model PIR); incoming photosynthetically active radiation (Kipp & Zonen, PAR-Lite). All instruments were mounted on a meteorological tower on top of the wheelhouse of the research icebreaker CCGS Amundsen.

During the ArcticNet annual cruises of the research icebreaker CCGS Amundsen, characteristics of the surface sea water (temperature, salinity, dissolved CO2 and O2) are monitored in conjunction with properties of the near-surface atmosphere (basic meteorological elements, incident radiation, CO2 concentration) to observe the relationship between the surface microclimate and the air-sea exchange, with particular interest in CO2. Central to this integrated dataset is an under-way sea water pCO2 system (General Oceanics 8050) attached to the ship's clean water intake. The following variables were measured continuously and logged at 1 minute intervals: pCO2sw (LI7000 gas analyzer); equilibrator water temperature; conductivity; pH; and, dissolved O2.

Raw backscatter data were collected from a CT25K ceilometer. A ceilometer is a device that uses a laser or other light source to determine the height of a cloud base. Ceilometers can also be used to measure the aerosol concentration within the atmosphere. Sampling took place from July to November 2009 in the southern Beaufort Sea and the Amundsen Gulf (Canadian Arctic) during the CFL cruise onboard the CCGS Amundsen icebreaker. The Circumpolar Flaw Lead System Study (CFL) is an IPY-funded project. Data were collected (1) during the ship transit, (2) set transects, (3) at several stations where we stayed 24 hours, and (4) at multi-day drift stations. The instrument was running continuously during the CFL project, with only minor interruptions for maintenance activities.

In July 2014 a Super Mohawk (SuMo) remotely operated vehicle (ROV) aboard the CCGS Amundsen was used to video-survey a deep-water environment at Home Bay. A video-transect ~2.2 km long was followed across depths of 700-750 m. Videos and photographs were obtained using a high-definition camera, and specimens of invertebrates (sponges) were collected using the ROV.

The CTD data was obtained during leg #0603 of the 2006 ArcticNet scientific cruise. The data were collected from October 28 to November 4, 2006, aboard the CCGS Amundsen. There were 22 casts, associated to 21 oceanographic stations, in the Labrador Sea and its fjords along the Canadian coast. The following parameters were measured: temperature, conductivity and pressure (with a Sea-Bird SBE-9plus), dissolved oxygen (Sea-Bird SBE-43), pH (Sea-Bird SBE-18-I), fluorescence (Seapoint chlorophyll fluorometer), nitrate concentration (Satlantic MBARI-ISUS 5T), transmittance (Wetlabs C-Star transmissiometer), 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.

The CTD data was obtained during the 2005 ArcticNet scientific cruise #0502. The data were collected from September 23 to October 16, 2006, aboard the CCGS Amundsen. There were 115 casts, associated to 79 oceanographic stations, in the Hudson Bay. The following parameters were measured: temperature, conductivity and pressure (with a Sea-Bird SBE-9plus), dissolved oxygen (Sea-Bird SBE-43), pH (Sea-Bird SBE-18-I), fluorescence (Seapoint chlorophyll fluorometer), 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.

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.

A video-survey using a Super Mohawk remotely operated vehicle (ROV) was conducted in October 2015 in Navy Board Inlet, 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 ~450 m along a transect line 480 m long.

Sample collection took place during both legs of the 2005 CCGS Amundsen cruise, during Leg 1 in 2006 and during Leg 3 in 2007. Water samples were collected using Teflon-lined Niskin bottles mounted on the ship¿s rosette system, at sites ranging from Hudson Bay, the North Open Water Polynya, the Northwest Passage and the Beaufort Sea. The water column was sampled at the surface, middle and bottom in 2005 and 2006 and at the surface and chlorophyll maximum in 2007. The resulting water chemistry dataset includes concentrations of total Hg, MMHg, DMHg and GEM in water. In addition, samples were also analyzed for sulfate and dissolved organic carbon in 2007 and for sulfate only in 2006. To quantify rates of biogeochemical Hg transformations in the water column, some water samples were amended with Hg stable-isotope tracers, namely 198Hg(II) and MM199Hg, and incubated on-board the ship for up to 25 hours before being preserved by acidification or freezing. Samples were then analyzed for MMHg, DMHg and GEM, using various mass-spectroscopy techniques at either the University of Alberta or Trent University. Thus, the rate of transformation of the 198Hg(II) tracer into MM198Hg, for example, could be quantified. This dataset includes rate constants for the following water column processes: the methylation of Hg(II) to MMHg, the methylation of MMHg to DMHg, the demethylation of MMHg, the reduction of MMHg to Hg(0) and the reduction of Hg(II) to Hg(0).