Beryllium-7 concentrations in snow during the MOSAiC expedition

• Main Author: Stephens, Mark
• Format: Dataset
• Language: English
• Published: PANGAEA 2022
• Subjects: Arctic Ocean; beryllium-7; error; central Arctic Ocean; DATE/TIME; Depth; bottom/max; top/min; Event label; frost flowers; Gamma spectrometry; LATITUDE; LONGITUDE; Mosaic; MOSAiC20192020; Multidisciplinary drifting Observatory for the Study of Arctic Climate; Polarstern; PS122/1; PS122/1_4-44; PS122/1_6-136; PS122/1_8-24; PS122/1_9-39; PS122/2; PS122/2_17-128; PS122/2_17-130; PS122/2_18-111; PS122/2_18-112; PS122/2_18-117; PS122/2_19-153; PS122/2_19-154; PS122/2_19-157; PS122/2_20-148; PS122/2_20-63; PS122/2_20-90; PS122/2_21-4; PS122/2_21-46; PS122/2_21-90; PS122/2_22-25; PS122/2_22-76; PS122/2_23-100; PS122/2_23-34; PS122/2_23-96; PS122/2_24-107; PS122/2_24-32; PS122/2_24-73; PS122/2_24-74; Arctic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.945412; https://doi.org/10.1594/PANGAEA.945412

For bulk snow samples, we collected the full snow column (snow surface to ice surface). First, the depth of snow was measured with a ruler. Next, a measured area of the snow surface was outlined with a stick or shovel. Then all snow (down to the ice surface) within the marked area was removed with a plastic ice scoop and placed in a plastic bucket. For snow profiles, we collected samples at different depth intervals within the snow column. After measuring the depth of snow and marking a measured area on the snow surface, the first layer of snow was carefully removed with a plastic flat bottomed ice scoop and placed in a bucket. The depth of the remaining snow was then measured with a ruler before collecting the next layer of snow. This process was repeated until the ice surface was reached. We sampled two to five layers per profile. All snow and frost flower samples were processed and analyzed using the same procedure. First, we added the following solutions: 5 ml hydrochloric acid, 2 ml iron chloride solution, and 1 ml of 1000 ppm stable beryllium AA standard (chemical yield tracer). After melting at room temperature, the water volume was measured using a graduated cylinder. Next, the sample was precipitated using ammonium hydroxide. After allowing the precipitate to settle, excess water was removed by decanting and centrifugation. Finally, the precipitate was transferred to petri dishes and placed in an oven for drying. The dried samples in petri dishes were counted by gamma spectroscopy. After gamma counting, samples were brought up to 1 liter in 1% nitric acid solution. The beryllium concentrations were then determined using a Perkin Elmer Optima 7300 DV ICP-OES. Our chemical yields averaged over 80%.