The data set is composed of raw files recorded with the Kongsberg Maritime SX90 long-range, low frequency (20-30 kHz) fisheries sonar during the CCGS Amundsen 2011 summer expedition in the Eastern Canadian Arctic. The sonar was operated during a 3 hours opportunistic survey offshore the Labrador coast on July 22nd and during a 18.75 hours opportunistic survey on July 30th. The sonar transducer is lowered 2.5 feet below the hull through a gate-valve. The cylindrical 256-elements transducer allows both a horizontal and a vertical sound transmission, and the omni-directional (horizontal) sonar beam can be tilted from +10 to -60 degrees to scan a large portion of the water column. The raw acoustic data were saved onto an external drive and print screens of interesting targets (fish schools and/or marine mammals) were recorded.

The data set is composed of raw files recorded with the Kongsberg Maritime SX90 long-range, low frequency (20-30 kHz) fisheries sonar during the CCGS Amundsen 2013 summer expedition in the Eastern Canadian Arctic. The sonar transducer is lowered 2.5 feet below the hull through a gate-valve. The cylindrical 256-elements transducer allows both a horizontal and a vertical sound transmission, and the omni-directional (horizontal) sonar beam can be tilted from +10 to -60 degrees to scan a large portion of the water column. The raw acoustic data were saved onto an external drive and print screens of interesting targets (fish schools) were recorded.

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

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.

This study presents sea surface concentrations of marine dimethylsulfide (DMS) measured across the Labrador Sea and the Canadian Arctic Archipelago during summer of 2017 (July-August). Using a novel automated instrument (ACT-MIMS) more than 2500 DMS observations were collected at high frequency alongside ancillary measurements of salinity, temperature, fluorescence (chlorophyll a proxy), solar radiation, ice concentration and the algal precursor of DMS, dimethylsulfoniopropionate. DMS concentrations ranged from ca. 1 to 32 nmol L-1 (average of 6 nmol L-1) in 2017 over an area covering a wide range of contrasting marine environments from coastal to open ocean, ice-free waters, as well as under-ice waters. Surface water DMS hotspots were measured in association with thermohaline oceanographic features in high productivity coastal waters, as well as with the presence of ponded first-year ice (FYI). Nighttime increases and daytime decreases of DMS concentrations were also observed in productive areas of the Labrador Sea and Davis Strait continental shelf. The association of DMS concentrations with diurnal solar radiation variation suggests the involvement of photobiological processes. Overall, our results strengthen the view that aqueous DMS cycling in the Arctic is intimately linked with sea ice dynamics and physiological responses to light. As such, future changes in the seasonality of the Arctic cryosphere will likely play an important role in shaping DMS emissions, although the sign and magnitude of the change remain highly uncertain.

Processed atmospheric ceiling heights were recorded from a CT25K ceilometer. The instrument was mounted on the CCGS Amundsen icebreaker on the port side directly behind the ship's wheelhouse. Data were collected during transit, set transects, 24-hour stations, and multi-day drift stations. The instrument was running continuously during the IPY-CFL project, with only minor interruptions for maintenance activities.

General description: A C-band polarimetric scatterometer was used to collect the backscattering signatures of new ice, first year ice, and multiyear ice in as many forms as possible during the fall freeze-up and winter period in Southern Beaufort Sea and Amundsen Gulf. This instrument is mounted on the port side of the ship (CCGS Amundsen) and the backscattering signatures were collected in conjunction with geophysical sampling of the region that was scanned in an attempt to provide the physical reasons for the electromagnetic interactions. This variable will be used in modeling studies and in coordinating in situ measurements with satellite data. Methology: The scatterometer measured the backscatter from the surface of interest. Incidence angles ranged from 20 to 60 degrees in 5 degree steps, with a swath of 60 degrees in the azimuth. Several scans were collected for statistical purposes (generally 5). Either during the scans, or immediately afterwards, geophysical sampling was performed in and around the region of the scan in order to gather ground truth data. Geophysical data are summarized in three metadata forms: CCIN Reference No 10108, 10097 and 1555. Data type: The dataset contains unprocessed and processed polarimetric data as a function of incidence angle.

Sample collection: The sampling was part of the Canadian Arctic Shelf Exchange Study (CASES) in which CCGS Amundsen was frozen in Franklin Bay in the coastal Beaufort Sea (Station FB/200) during winter. Upper mixed-layer microbial plankton communities were sampled 5m below the water surface using the ship CTD rosette system equipped with 12L Niskins during openwater conditions. During the time that the ship was frozen in Franklin Bay from December 2003 to early June 2004, samples were taken using a 5L Niskin bottle from 3m below the bottom ice through a 300mm hole that had been drilled 500m upstream of the ship. HPLC pigment analysis: One to two liter samples of water were filtered onto Whatman GF/F filters and stored frozen at -80C until analysis. Phytoplankton pigments on the GF/Fs were extracted in 3mL of 95 percent MeOH and 100 uL of the extracts was injected into a Varian ProStar HPLC equipped with a Symmetry C8 column. The HPLC peaks were detected by diode-array spectroscopy (350-750nm) and absorbance chromatograms were obtained at 440 (for chls) and 450nm (for carotenoids). Chlorophylls were also detected by fluorescence (excitation: 440nm; emission: 650nm). The HPLC solvent protocol was based on gradient dilution with two solvent mixtures (Zapata et al. 2000): a methanol, acetonitrile, and aqueous pyridine (50:25:25 v:v:v) solution; and a methanol, acetonitrile, and acetone (20:60:20 v:v:v) solution. The flow rate was 1mL/ min, and the equilibration time was 7min.

General description: A C-band polarimetric scatterometer was used to collect the backscattering signatures of new ice, first year ice, and multiyear ice in as many forms as possible during the fall freeze-up and winter period in Southern Beaufort Sea and Amundsen Gulf. This instrument is mounted on the port side of the ship (CCGS Amundsen) and the backscattering signatures were collected in conjunction with geophysical sampling of the region that was scanned in an attempt to provide the physical reasons for the electromagnetic interactions. This variable will be used in modeling studies and in coordinating in situ measurements with satellite data. Methology: The scatterometer measured the backscatter from the surface of interest. Incidence angles ranged from 20 to 60 degrees in 5 degree steps, with a swath of 60 degrees in the azimuth. Several scans were collected for statistical purposes (generally 5). Either during the scans, or immediately afterwards, geophysical sampling was performed in and around the region of the scan in order to gather ground truth data. The dataset contains unprocessed and processed polarimetric data as a function of incidence angle.

The Belcher Glacier seabed mapping program was carried out over a 12-hour period in September 2006 and consisted of: 1) imaging of deeper parts of the inlet using the EM300 30 kHz multibeam sonar on the CCGS Amundsen icebreaker; and 2) detailed mapping adjacent to the tidewater front using the 300 kHz multibeam launch CSL Heron. Data files from this mapping project are archived in ASCII, ESRI, and GTIF formats."