IMOS - SOOP Ocean Carbon Dioxide Data from RV Aurora Australis voyage AA2011VMS (Hobart-Hobart)

This data was collected in January/February 2011 by the IMOS Ship of Opportunity Underway CO2 Measurement research group on RV Aurora Australis (IMOS platform code: VNAA) voyage AA1011_VMS.\n\nDeparted: \tHobart, Tasmania, \t \tJanuary 04, 2011\nArrived: \tHobart, Tasmania, \t\tFebruary 07, 2011\n\nCO2 System Overview:\nThe fugacity of carbon dioxide (fCO2) in surface seawater was measured using a General Oceanics Inc. automated system (Model 8050; Pierrot et al 2009). Seawater is sprayed into an equilibration chamber and CO2 in the headspace gas equilibrates with the seawater. The headspace gas is pumped through a thermoelectric condenser followed by a nafion drying tube before flowing through a Licor 7000 non-dispersive infrared gas analyser used to measure the CO2 mole fraction (XCO2) of the dried air. The gas flow is stopped temporarily for the CO2 measurements, which are made at atmospheric pressure. A set of four CO2 standards that cover the range of CO2 values expected in the ocean are analysed about every three hours to calibrate the gas analyser. Atmospheric XCO2 (dry) is measured after the standards by pumping clean outside air from an intake on the forward mast of the ship. \n\nSeawater intake and ancillary data:\nThe seawater intake is at about 6 m depth. A remote temperature sensor (Seabird Electronics SBE38) located at the intake is used to measure sea surface temperature (SST). Sea surface salinity is measured using a thermosalinograph (Seabird Electronics SBE21) mounted in the oceanographic lab next to the pCO2 system. The travel time between the intake and CO2 system is typically about 70 seconds with warming usually less than 0.7ºC in cold waters near freezing. The thermosalinograph water is from the same intake and supply line. \n\nMeteorological data, salinity, SST, and ships position and time are taken from the ship’s logging system.

本数据集由澳大利亚海洋综合观测系统（Integrated Marine Observing System, IMOS）的船舶走航CO₂测量研究组，于2011年1月至2月期间，在“南极光号”（RV Aurora Australis，IMOS平台编号：VNAA）的AA1011_VMS航次中采集。

起航：塔斯马尼亚州霍巴特，2011年1月4日
抵达：塔斯马尼亚州霍巴特，2011年2月7日

二氧化碳测量系统概况：
表层海水二氧化碳逸度（fugacity of carbon dioxide, fCO₂）采用General Oceanics公司自动化测量系统（型号8050；参考Pierrot等2009年研究）进行测定。具体流程为：将海水喷入平衡腔，使顶空气体中的CO₂与海水达到气液平衡；随后将顶空气体泵送至热电冷凝器，经纳菲隆干燥管除湿后，流经Licor 7000型非色散红外气体分析仪，以测量干燥空气中的CO₂摩尔分数（XCO₂）。CO₂测量环节会暂时中断气流，且所有测量均在大气压下完成。每约3小时会分析一组覆盖海洋典型CO₂浓度范围的4种标准CO₂气体，用于校准气体分析仪。完成标准气体校准后，通过船舶前桅杆的进气口抽取外部清洁空气，以测定干燥大气中的XCO₂。

海水取水口及辅助观测数据：
海水取水口深度约为6米。取水口处搭载有Seabird Electronics公司SBE38型远程温度传感器，用于测量海表温度（sea surface temperature, SST）。紧邻pCO₂（partial pressure of carbon dioxide）测量系统的海洋学实验室内，安装有Seabird Electronics公司SBE21型流动式温盐计，用于测定海表盐度。从取水口至CO₂系统的输水行程耗时通常约70秒，在接近冰点的寒冷水域中，输水过程中水温升高通常小于0.7℃。流动式温盐计的供水来自同一取水口及输水管道。

气象数据、盐度、海表温度、船舶位置及时间信息均取自船舶日志系统。