Imaged brine inclusions in young sea ice—Shape, distribution and formation timing

Abstract

a b s t r a c t a r t i c l e i n f oLiquid inclusions in sea ice are variable and dependent on the myriad of physical conditions of the atmospheresea 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.

Oxygen fluxes beneath Arctic land-fast ice and pack ice: towards estimates of ice productivity

“…The accumulated brines percolate through the ice matrix and under the action of gravity are forced downward, forming vertical interlinked channels through the ice and draining to the underlying waters. Sea-ice is therefore largely depleted of dissolved salts and gases, but the brine channels form a mosaic of microsites within the ice pack which typically are at or close to saturation with respect to dissolved gases (Glud et al 2002;Zhou et al 2014;Galley et al 2015). Colder ice temperatures favor low brine volume, high brine salinity, and low permeability of the ice matrix (Cox and Weeks 1983).…”

Visualizing brine channel development and convective processes during artificial sea-ice growth using Schlieren optical methods

“…The use of a Hele-Shaw cell, although an advantage for imaging purposes as it allows light to pass through the ice, has certain potential drawbacks: the inherently 3-D process of brine channel formation (Lake and Lewis, 1970;Galley and others, 2015) is confined in a quasi-2-D geometry.…”

“…However, this quasi-2-D system could result in specific limitations compared with the 'real world' situation: 3-D brine channels will not be able to develop as they would in natural sea ice. The 3 mm depth should not hamper the development of the main channel collector (usually millimetric in size), but will restrict the development of its symmetrical 3-D network of feeding channels (Lake and Lewis, 1970;Galley and others, 2015), and therefore its volume and output when compared with the natural case. However, we believe that transport processes and mass-balance calculations based on brine velocities of incoming and outgoing brine within the cell should remain internally coherent.…”

Vertical distribution of brine and volume structure thin one year ice Amur bay on base NMR and MRT dates

“…Приведено новое эмпирическое соотношение для расчета всей толщины и отдельных прослоек льда применительно к тонким молодым льдам. лов и пор по размеру, что было бы невозможно осуществить с помощью традиционных методов [6,[8][9][10][11][12]. В частности, этим методом установлены закономерности замерзания искусственной МВ и фазовый состав льда в бассейне довольно крупного размера (18,2×9,1×2,75 м) [9].…”

“…Ветвистую пространственную структуру льда, но ниже срединного слоя, наблюдали и в экспериментах с замораживанием искусственной МВ в бассейне [9]. Аналогичные картины кристаллических образований наблюдались на МРТ изображениях кернов, извлеченных из однолетних льдов в феврале 2017 и 2018 гг., что указывает на устойчивую тенденцию в формировании внутренней структуры льда.…”