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 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 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 project, the following variables were measured continuously at 1 minute intervals using a custom-built pCO2 equilibrator attached to the ship's clean water intake: -pCO2sw (LI7000 gas analyzer) -Equilibrator water temperature

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 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.

Replicate cores spanning the entire thickness of the floe were taken from a single sampling site on a multi-year sea ice floe in the southwestern Beaufort Sea in August 2011 as part of the ArcticNet 2011 cruise of the CCGS Amundsen. Quantification of total mercury (THg), methylmercury (MeHg), Chlorophyll a, dissolved organic carbon (DOC) and delta 18O was performed on separate cores, and temperature and salinity profiles were recorded. THg was analyzed via CVAFS on board the Amundsen in the Portable In-situ Lab for Mercury Speciation (PILMS), while MeHg was analyzed via GC-CVAFS in the Ultra-Clean Trace Elements Lab (UCTEL) at the University of Manitoba. Chlorophyll a concentrations were analyzed onboard the Amundsen via fluorimetry, and salinity was recorded using a Hach Sension probe. DOC was analyzed by Dr. Michel Gosselin's lab at the Université du Québec à Rimouski via a high-temperature combustion Shimadzu TOC-5000A autoanalyzer. Delta 18O analysis was performed by G.G. Hatch Isotope Laboratories, University of Ottawa, Canada. Samples and standards (calibrated against several samples of Vienna - SMOW) were flushed with a gas mixture of 2 % CO2 in helium off-line, equilibrated at 21°C for 5 d, then analyzed using the Gasbench + DeltaPlus XP isotope ratio mass spectrometer (ThermoFinnigan, Germany).

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 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

Samples collected by rosette or hand-deployed niskin, directly transferred into acid-washed and backed glass vials with teflon-lined silicone septa caps, and frozen at -20 or -80 C. Analyses conducted by high-temperature catalytic combustion and calibrated again standards provided by the University of Miami. In 2002, all samples were total organic carbon (TOC), and in 2003-04, all samples were dissolved organc carbon (DOC, filtered through combusted GFF), and TOC was also collected at full stations at in surface waters at the overwintering site.

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.