Viscosity of brine samples taken from 2 MHz to 4 GHz across a range of temperatures during the SIPEX II voyage of the Aurora Australis, 2012

Brief description

This dataset contains data resulting from the measurement of brine samples extracted from the sea-ice during the 2012 SIPEX 2 (Sea Ice Physics and Ecosystems Experiment) marine science voyage. The Brine was collected from partially drilled holes in the ice using suction. In some of these cases the brine analysed came from holes which correspond to permeability measurements. In these cases a core number is associated with the brine data which will correspond to the core number in the permeability data set found in the master core list Excel file. The purpose of this data set was to act as a first step to quantify the effect that extra cellular carbon may have on the physical properties of brine and sea ice. At least 1 litre of brine was collected from each partial hole for analysis. The total sample was split for the following analyses. Viscosity of the brine was measured before and after filtering out any biological components that may have been in solution or otherwise in order to assess whether or not extracellular carbon has an effect on fluid flow in sea ice. What was not used for viscosity measurements was used for chlorophyll, extra-cellular carbon and bacterial analysis to gain a sense of the level and type of biology and biological compounds in the brine to then be compared to the measured physical properties. The biological analysis will be carried out at the university of Tasmania by Sarah Ugalde. On many of these samples the complex permittivity of the brine was also measured and the data can be found in the Relative_Permitivity_of_Brine folder with each sample corresponding in core number. For info on the permittivity measurements please see the metadata in that folder.

Lineage

Progress Code: completed

Statement: For some of the samples the salinity was very close to that of sea water indicating that ocean water from below had made its way into the brine sample. This would most likely be a problem for the samples from site 4 as the brine was collected at the termination of the permeability experiments which last on the order of 20 min to 1 hour. For the samples at station 7 the permeability experiments were shortened in an attempt to prevent sea water from filling the hole however for deep holes this likely unavoidable. A further complication is the need for at least 1 litre of brine in order to complete the biological experiments,for deeper holes there might not be 1 litre of brine in the ice before sea water makes its way up into the hole. Brine from site 8 however was collected as it came from the partial hole at shallow depth in low quantity and should not have sea water in it. During measurement in the lab temperature was difficult to hold constant but was constantly monitored and recorded. For salinities over 70PSU measurement had to be made by watering down a part of the sample rather than direct measurement from a salinometer.