Continuous air samples were collected on Leg 1 of the CCGS Amundsen cuise in 2007 using a high volume air sampler that drew air through a glass fibre filter followed by two polyurethane foam plugs. Water samples were collected by filter water through a glass fibre filter followed by a solid phase absorbent. Samples were extracted back at the laboratory followed by analysis using a gas chromatograph-mass spectrometer. Data generated included concentration of semi-volatile contaminants in air and water and chiral signature of chiral components.

The CTD data was obtained during the 2007-2008 ArcticNet scientific cruise #0704. The data were collected from August 5 to 16, 2007, aboard the CCGS Amundsen. There were 20 casts, associated to 17 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.

Sediment from Hudson Bay was collected with boxcores deployed from the CCGS Amundsen. The boxcores were immediately sectioned at 1 cm (top 10 cm), 2 cm (10 cm to 20 cm depth), or 5 cm (depth > 20 cm) intervals, and aliquoted for a variety of analyses. Sediment samples were then frozen (-20 Celsius) while onboard for approximately 1 month, followed by freeze-drying at the Freshwater Institute, Department of Fisheries and Oceans, Winnipeg, MB, Canada. Freeze-dried sediment was stored at room temperature in the dark. Rock Eval pyrolysis of freeze dried sediment samples was performed at the Geological Survey of Canada using a Rock Eval 6 pyrolysis.

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 platform above the wheelhouse of the 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 -dissolved O2

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 the bow of the research icebreaker CCGS Amundsen

The data set is composed of raw files recorded with a SIMRAD EK60 three-frequency split-beam echosounder that was operated continuously during the annual ArcticNet (2005-2013) sampling expeditions in the Canadian Arctic and Subarctic aboard the CCGS Amundsen. Three 7° transducers were hull-mounted, two in oil-filled arctic wells protected by a 2.5 cm thick acoustically transparent polycarbonate plate (38 and 120 kHz) and one in a Traveocean piston well in direct contact with water (200 kHz). The acoustic signal was recorded continuously on a PC using ER60 software version 2.0.0. Ping interval was set at 2 or 3 s and the pulse length was set at 1.024 ms.

Water samples were collected at approximately 0.3 m depth at all stations in Hudson Bay during the the 2010 cruise from Kuujjuarapik, PQ to Churchill, MB. We collected samples at basic, mooring and CTD (conductivity-temperature-depth) stations, as well as along two transects made by Zodiac near the mouth of the Rivière de la Grande Baleine and off Cape Tatnam, located at ca. 100 km East of the Nelson River. All water samples were filtered on board, and subsamples were retained for analysis for dissolved and particulate organic carbon and nitrogen, as well as for phosphate, total soluble salts (TSS), chlorophyll a, CDOM (absorbtion and fluorescence spectra), oxygen-18 and salinity. At each station, water column profiles were recorded, each to the bottom or at least 30 m depth, using an Idronaut CTD with conductivity, temperature, depth and turbidity sensors, and a WetLabs ECO Fluorometer for CDOM fluorescence. In addition,we made several water column profiles of absorption and attenuation spectra off the mouth of the Rivière de la Grande Baleine, using a WetLabs hyperspectral absorption and attenuation meter (WetLabs acs). We also recorded miscellaneous water surface reflectance spectra, using a Satlantic HyperSAS instrument mounted on the ship's bow, near Rivière de la Grande Baleine, near the mouth of James Bay and in the outer estuary of the Nelson River.

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.

Sediment cores were collected onboard the CCGS Amundsen during ArcticNet cruise 0502 (2005) using a box corer, penetrating the seafloor to a maximum of 50 cm. Samples were stored in a freezer (- 20 °C) onboard the Amundsen until the end of the cruise, then shipped to the Freshwater Institute (FWI), where they were maintained in storage at - 20 °C. Subsamples were processed at the University of Victoria Marine Micropaleontology Laboratory in October-November 2010. A gentle version of the standard palynological protocol was applied to oven-dried samples of known volume. Steps are as follows: (1) add 10 % hydrochloric acid in room temperature; (2) sieve with distilled water through a 120 micrometre and a 15 micrometre nitex mesh, retaining the fraction in between; (3) add 48% hydrofluoric acid in room temperature for 2-4 days followed by 20 minutes in 10 % hydrochloric acid; (4) sieve through precise 15 micrometre mesh with gentle sonication for 10-60 seconds. The final residue of samples was placed in sealed storage vials and stored in + 4 °C. Aliquots of residue were mounted in glycerine jelly on microscopic slides with cover slips. Dinoflagellate cysts are studied primarily with Zeiss Standard 20 microscope under bright-field oil-immersion and 500X and 1000X magnifications. At least 300 dinoflagellate cysts species and cyst types will be identified on each slide together with pollen, freshwater algae and other palynomorphs.