Carbon dioxide flux measurements from a seasonally sea ice-covered marine environment in the Canadian Arctic

This dataset contains air-sea fluxes of carbon dioxide measured from a 10-m eddy covariance tower installed on Qikirtaarjuk Island (68.983865°N, 105.834880°W), located in Dease Strait roughly 35 km west of Cambridge Bay, Nunavut in the Canadian Arctic Archipelago. The measurements cover the period from May 2017 to October 2018. A detailed description of the instrument setup can be found in Butterworth and Else (2018). Measurements of CO2 flux were obtained using a 3-D ultrasonic anemometer (CSAT3; Campbell Scientific) and a closed-path infrared gas analyzer (LI-7200; Licor). The flux instruments were mounted at 9.5 m above ground level. Flux measurements were calculated for 20-minute intervals. The supporting meteorological data represent 20-minute averages corresponding to the flux intervals. 

Variables (Name/Description)

year
year (MST)

month
month (MST)

day
day (MST)

hour
hour (MST)

minute
minute (MST)

second
second (MST)

sic
sea ice concentration (%; GoPro - Hero4 and Campbell Scientific - CC5MPX)

sic_AMSR2
sea ice concentration (%; AMSR2 satellite product [Spreen et al. 2008])

xco2
CO2 mixing ratio (µatm; LI-COR – LI-7200 intake at 9.5 m agl)

fco2
CO2 flux (mmol m-2 d-1)

ustar
friction velocity (m s-1; Campbell Scientific - CSAT3 mounted 9.5 m agl)

ws
wind speed - 3D sonic (m s-1; Campbell Scientific - CSAT3 mounted 9.5 m agl)

wd
wind direction - 3D sonic (°; Campbell Scientific - CSAT3 mounted 9.5 m agl)

ws_prop
wind speed - prop vane (m s-1; RM Young - Marine Wind Monitor mounted 7.8 m agl)

wd_prop
wind direction - prop vane (°; RM Young - Marine Wind Monitor mounted 7.8 m agl)

T
air temperature (°C; Campbell Scientific - CSAT3 mounted 9.5 m agl)

rh
relative humidity (%; Campbell Scientific - HMP45C mounted 9.6 m agl)

pressure
atmospheric pressure (mbar; LI-COR - LI-7500 electronics box 2 m agl)

kdn
incoming SW radiation (W m-2; Kipp & Zonen - CNR4 was mounted 2.8 m agl)

kup
outgoing SW radiation (W m-2; Kipp & Zonen - CNR4 was mounted 2.8 m agl)

Note: The CO2 flux variable (fco2) shows only values that passed the quality control criteria described in Butterworth and Else (2018). Missing / bad data points are represented as -999.