BC concentrations and size distributions in the surface snow of Syowa and Mizuho route in 2011

This data set is the concentrations and size distributions of BC and inorganic ions in snow samples collected at the Syowa station in Antarctica from April to December 2011 and along a traverse route to an inland (Mizuho) station (S16, H280 and Mizuho) in October. The sampling point at the Syowa station was located 400 m east of the main area and 35 m upwind from the "clean air observatory". Samples were collected from surface snows ~1-10 cm in depth using glass containers by the 52nd Japanese Antarctic Research Expedition (JARE52, 2010-2012). These samples were kept below -20 degreeC until the analyses performed at the National Institute of Polar Research (NIPR) in Japan. Snow samples that were not directly in contact with the inner wall or the lid of the container was crushed using a ceramic knife and distributed to four containers at a class 100 clean booth in the low-temperature laboratory of the NIPR; three glass containers for SP2 analysis and one low-density polyethylene (LDPE) container for inorganic ion analysis. Then, the samples were melted in a refrigerator at 5 degreeC and sonicated for 15 minutes. All tools and containers used for sample handling were sonicated for 15 minutes with acetone and ethanol and then with ultra-pure water. The mass and number concentrations of BC (CMBC and CNBC) in the snow samples and BC size distributions were analyzed using two modified nebulizer/single particle soot photometer (SP2, Droplet Measurement Technology, Boulder, Colorado, USA) at the NIPR and te Univesity of Tokyo. BC particles were aerosolized by a concentric pneumatic nebulizer (Marin-5, Cetac Technologies Inc., Omaha, Nebraska, USA) at a water flow rate of 3.0 microL s-1 to introduce into the SP2 at a flow rate of 16 cm3 s-1. Inorganic ion concentrations (Cl-, NO2-, Br-, NO3-, SO42-, Na+, NH4+, Mg2+, Ca2+, and K+) were measured using an ion chromatograph (IC-2010, Tosoh, Co., Ltd., Tokyo, Japan). The limit of detection (LOD) values of CMBC for the SP2 analysis were defined as the averaged values of three pure water samples (blank samples), and values of 32.7 ng L-1 and 41.0 ng L-1 were obtained for the SP2/Nebulizer systems at the University of Tokyo and the NIPR, respectively. The LOD values (S/N=3) for cations were 6.1, 17.2, 16.0, 20.3 and 42.3 ppb for Na+, NH4+, Mg2+, Ca2+ and K+, respectively. The LOD values for anions were 4.2, 10.5, 14.5, 8.5 and 17.9 ppb for Cl-, NO2-, Br-, NO3- and SO42-, respectively. The average CMBC and CNBC between April and November were 288.2 ng L-1 and 101.5 particle mL-1, respectively, and those during December were 2117.3 ng L-1 and 812.7 particle mL-1, respectively. The CMBC and CNBC of the traverse route samples were 1.7 -2.7 times higher than those of the Syowa samples collected during the same period, at 727.7 -1153.2 ng L-1 and 249.6 - 454.6 particle mL-1, respectively. The average mBC was 2.8 (1.8 - 5.8) fg particle-1, which is smaller than typical values in the Arctic. This data was published by Kinase et al. (2019).本数据集涵盖2011年4月至12月于南极昭和站采集的雪样，以及同年10月沿前往内陆瑞穗站（S16、H280及瑞穗站）的考察路线采集的雪样中黑碳（BC）的浓度与粒径分布、无机离子浓度数据。 昭和站的采样点位于主区域东侧400米处，距“洁净大气观测站”上风向35米。样品由第52次日本南极考察队（JARE52，2010-2012）采用玻璃容器采集，采集对象为深度约1~10 cm的表层积雪。 所有样品均保存于-20℃以下，直至在日本国立极地研究所（NIPR）开展分析。未直接接触容器内壁与盖子的雪样，在国立极地研究所低温实验室的100级洁净室中，以陶瓷刀粉碎后分装至4个容器：3个玻璃容器用于单颗粒炭黑光度计（SP2）分析，1个低密度聚乙烯（LDPE）容器用于无机离子分析。随后将样品置于5℃冰箱中融化，并超声处理15分钟。所有用于样品处理的工具与容器均先后以丙酮、乙醇及超纯水超声清洗15分钟。 雪样中黑碳的质量浓度（CMBC）、数浓度（CNBC）及粒径分布，分别在国立极地研究所与东京大学使用两台改装后的雾化器/单颗粒炭黑光度计（SP2，Droplet Measurement Technology，美国科罗拉多州博尔德市）完成分析。黑碳颗粒通过同心气动雾化器（Marin-5，Cetac Technologies Inc.，美国内布拉斯加州奥马哈市）以3.0 μL·s⁻¹的水流速率雾化，以16 cm³·s⁻¹的流量引入SP2。无机离子（Cl⁻、NO₂⁻、Br⁻、NO₃⁻、SO₄²⁻、Na⁺、NH₄⁺、Mg²⁺、Ca²⁺、K⁺）浓度采用离子色谱仪（IC-2010，日本东曹株式会社，东京）测定。SP2分析的CMBC检出限（LOD）以3份纯水空白样品的平均值定义，东京大学与国立极地研究所的SP2/雾化器系统的检出限分别为32.7 ng·L⁻¹和41.0 ng·L⁻¹。阳离子的检出限（S/N=3）：Na⁺为6.1 ppb、NH₄⁺为17.2 ppb、Mg²⁺为16.0 ppb、Ca²⁺为20.3 ppb、K⁺为42.3 ppb。阴离子的检出限：Cl⁻为4.2 ppb、NO₂⁻为10.5 ppb、Br⁻为14.5 ppb、NO₃⁻为8.5 ppb、SO₄²⁻为17.9 ppb。 4月至11月的CMBC与CNBC平均值分别为288.2 ng·L⁻¹和101.5 颗粒·mL⁻¹，12月的平均值分别为2117.3 ng·L⁻¹和812.7 颗粒·mL⁻¹。考察路线样品的CMBC与CNBC分别为727.7~1153.2 ng·L⁻¹和249.6~454.6 颗粒·mL⁻¹，较同期采集的昭和站样品高1.7~2.7倍。平均单位颗粒黑碳质量（mBC）为2.8（1.8~5.8）fg·颗粒⁻¹，低于北极地区的典型值。本数据集由Kinase等人（2019）发表。