Particulate organic matter elemental analysis, mixed layer, during the K-Azis voyage of the Aurora Australis au1603

Water samples of 1 to 2L from Niskin bottles filled close to the surface, mid mixed layer depth and bottom of the mixed layer were drawn cleanly through a 210um mesh to exclude zooplankton. All samples were filtered as two size fractions, 1.2 to 20um (larger particles excluded by 20um Nitex mesh) and a separate 1.2 to 210um total sample. The filters were 1.2um silver membranes (Sterlitech) 13mm diameter. The samples were preserved by drying at 60C in a dedicated clean oven. Prior to encapsulation, a 5mm diameter subsample was taken for biogenic silica analysis, which is delayed until there has been evaluation of the particle data from the flow cam and UVP. Samples were encapsulated in silver (Sercon sc0037) after acidification and drying. The decarbonated encapsulated POC samples were analysed by elemental analyser at the CSL UTAS by Dr Thomas Rodemann (EA TCD 960C, single point standardisation every 12 samples).  EA detection limit 0.001umol POC. POC and PON are presented as molar units. Blanks were process blanks (seawater) and 7% of the average for the combined data n=177. 1sd=0.12uM.

The ctd casts were all given the prefix K, so K001, K002 etc. Not all stations were sampled due to budget constraints. Niskin is the Niskin bottle number.

从采集于表层、混合层中部及混合层底部的尼斯金采水器（Niskin bottle）中获取1~2L水样，经210μm筛网洁净过滤以去除浮游动物。所有水样均按两个粒径组分进行过滤：其一为1.2~20μm组分（通过20μm尼泰克斯筛网（Nitex mesh）截留较大颗粒），另一组为单独的1.2~210μm总样组分。所用过滤膜为直径13mm的1.2μm银膜（Sterlitech）。水样保存方式为置于专用洁净烘箱中60℃烘干。封装前，切取直径5mm的子样用于生物硅分析，该分析将暂缓至完成流式颗粒成像分析仪（flow cam）与水下可视剖面仪（UVP）的颗粒数据评估后再进行。水样经酸化与烘干后，采用银质封装材料（Sercon sc0037）进行封装。经脱碳处理的封装颗粒有机碳（POC）样品，由托马斯·罗德曼博士（Dr Thomas Rodemann）在塔斯马尼亚大学（UTAS）的CSL实验室采用元素分析仪完成检测（仪器型号为EA TCD 960C，每12个样品执行一次单点校准）。该元素分析仪的检测限为0.001μmol POC。颗粒有机碳（POC）与颗粒有机氮（PON）均以摩尔单位进行表征。空白样品为海水流程空白，其数值为合并数据集（n=177）平均值的7%，标准偏差1sd=0.12μM。
所有温盐深剖面仪（CTD）站位均冠以前缀K，例如K001、K002等。受经费限制，并非所有站位均完成采样。文中所述"Niskin"指尼斯金采水器编号。