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Liquid inclusions in sea ice are variable and dependent on the myriad of physical conditions of the atmosphere–sea ice environment in which the sea ice was grown, and whether or not melting processes affected the sea ice. In that light, there exist relatively few observations and resultant quantification of the morphology and vertical distribution of brine inclusions in sea ice. Using a magnetic (3.0 T) resonance (MR) imager using constructive interference steady state gradient echo sequence, we show that it is possible to image brine channels and pockets in an 18.5 cm young sea ice core in three-dimensions in only four and a half minutes following core storage at − 20 °C. We present a three-dimensional image of a brine drainage channel feature in a young sea ice core, give the physical context for its formation by presenting the physical conditions of the atmosphere and water/sea ice prior to sea ice growth through the sampling date, and observe its physical characteristics. We illustrate that brine drainage channels may be established concurrently with ice growth, and indicate the amount and location of vertical and horizontal fluid connectivity in the young sea ice sample in the context of the environment in which it grew. Finally, we show that a vertical brine volume distribution profile can be calculated using MR image data, extending the (non-imaging) nuclear magnetic resonance work of others in this vein. [ABSTRACT FROM AUTHOR]

Turbulent exchanges under sea ice play a controlling role in ice mass balance, ice drift, biogeochemistry, and mixed layer modification. In this study, we examined the potential to measure under-ice turbulent exchanges of heat, salt, momentum, and dissolved oxygen using eddy covariance in an experimental sea ice facility. Over a 15-day period in January 2013, an underwater eddy covariance system was deployed in a large (500 m 3 ) in-ground concrete pool, which was filled with artificial seawater and exposed to the ambient (− 5 to − 30 °C) atmosphere. Turbulent exchanges were measured continuously as ice grew from 5 to 25 cm thick. Heat, momentum, and dissolved oxygen fluxes were all successfully derived. Quantification of salt fluxes was unsuccessful due to noise in the conductivity sensor, a problem which appears to be resolved in a subsequent version of the instrument. Heat fluxes during initial ice growth were directed upward at 10 to 25 W m − 2 . Dissolved oxygen fluxes were directed downward at rates of 5 to 50 mmol m − 2 d − 1 throughout the experiment, at times exceeding the expected amount of oxygen rejected with the brine during ice growth. Bubble formation and dissolution was identified as one possible cause of the high fluxes. Momentum fluxes showed interesting correlations with ice growth and melt but were generally higher than expected. We concluded that with the exception of the conductivity sensor, the eddy covariance system worked well, and that useful information about turbulent exchanges under thin ice can be obtained from an experimental sea ice facility of this size. [ABSTRACT FROM AUTHOR]