Snow stable water isotopes of a sublimation sampling scheme at the EastGRIP deep drilling site, summer season 2019

Snow samples were taken along a 90 m transect at the EastGRIP ice core deep drilling site perpendicular to the prevailing wind direction.The snow was collected after precipitation events from the very surface (0 - 0.5 cm) and from the top centimeter at 10 positions with 10 m spacing. The samples were shipped frozen to the Alfred-Wegener-Institute and stored at -25 °C. Prior to measurements the samples were melted in the sample bags at room temperature. For the measurement of the isotopic composition a Picarro L2120-i, a Picarro L2140-i and a Picarro L2130-i with a high-throughput vaporizer (model A0212) was used. The measurement set-up followed the Van-Geldern protocol (van Geldern and Barth, 2012). Each sample was injected four times and the standard deviation is computed. We calculate the average over all the standard deviations as a measure of uncertainty. We find this average to be 0.03 permil for δ18O (with stdev 0.02) and 0.13 permil for δD (stdev 0.11). The maximum standard deviation within the data set was found to be 0.10 for δ18O and 0.8 for δD. As a measure of accuracy the off-set between the defined and measured value of the quality check standard for each measurement run is provided. We calculate the average of this off-set for the whole data set and obtain a value of -0.04 permil for δ18O (stdev 0.07) and -0.6 permil for δD (stdev 0.4). The maximum off-set found within the data set was 0.18 permil for δ18O and -1.5 permil for δD.