IMOS - SOOP Ocean Carbon Dioxide Data from RV Southern Surveyor voyage ST032009

This data was collected in October 2009 by the IMOS Ship of Opportunity Underway CO2 Measurement research group on RV Southern Surveyor (IMOS platform code: VLHJ) voyage ST032009.\n\nDeparted: \tHobart, Tasmania, October 10, 2009\nArrived: \tSydney, New South Wales, October 14, 2009\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 four hours to calibrate the gas analyser. The standard gas concentrations are on the WMO-X2007 mole fraction scale for CO2-in-air. 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 located at about 5.5m depth in the bow of the ship. Sea surface salinity is measured using a thermosalinograph (Seabird Electronics SBE21) located next to the CO2 system. A remote temperature sensor (Seabird Electronics SBE 38) located at the intake is used to measure sea surface temperature (SST). The travel time between the intake and CO2 system is typically about 4 minutes with warming usually less than 0.6ºC. The thermosalinograph water is from the same intake, but the supply lines separate after the intake. A comparison of thermosalinograph and equilibrator temperature records shows the temperature difference in the two lines is generally less than 0.1ºC. The thermosalinograph water line travels outside the ship and is typically warmer than the equilibrator. The travel time in water line to the thermosalinograph is 2.5 minutes faster than to the equilibrator. \n\nMeteorological data, salinity, SST, and ships position and time are taken from the ships logging system. These parameters and the data quality are maintained by the Australian Marine National Facility.本数据集由IMOS机遇船舶走航CO₂测量研究组于2009年10月，在RV Southern Surveyor科考船（IMOS平台代号：VLHJ）的ST032009航次中采集完成。 启航地点：塔斯马尼亚州霍巴特，2009年10月10日 抵达地点：新南威尔士州悉尼，2009年10月14日 CO₂监测系统概况： 本研究采用General Oceanics公司生产的自动化CO₂测量系统（型号8050；参考Pierrot等人2009年研究），对表层海水的二氧化碳分压（fCO₂）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；随后将顶空气体经热电冷凝器、纳菲昂干燥管进行除湿处理，再通入Licor 7000型非色散红外气体分析仪（non-dispersive infrared gas analyser），以测定干燥空气的CO₂摩尔分数（XCO₂）。测量过程中会暂时中断气流，所有测定均在大气压下完成。每间隔约4小时，将使用覆盖海洋环境预期CO₂范围的4组标准气体对气体分析仪进行校准。标准气体的浓度基于WMO-X2007空气CO₂摩尔分数标度进行标定。在完成标准气体校准后，通过船舶前桅的进气口抽取洁净外部空气，以测定大气干燥态XCO₂。 海水取样与辅助数据： 海水取样口位于船舶船艏约5.5米水深处。紧邻CO₂系统处安装有热盐深仪（thermosalinograph，Seabird Electronics SBE21），用于测定海表盐度；取样口处还部署了远程温度传感器（remote temperature sensor，Seabird Electronics SBE 38），以获取海表温度（SST）。从取样口到CO₂系统的输水耗时通常约4分钟，其间水温升高通常低于0.6℃。热盐深仪的供水同样取自该取样口，但输水管道在取样口后即与CO₂系统的输水管道分离。对热盐深仪与平衡腔的温度记录进行对比后发现，两条输水管道间的温差通常小于0.1℃。热盐深仪的输水管道沿船舶外壁铺设，通常温度高于平衡腔输水管道；其输水耗时比到平衡腔的输水耗时快2.5分钟。 气象数据、盐度、海表温度以及船舶位置与时间信息均取自船舶日志系统。上述参数及数据质量由澳大利亚海洋国家设施（Australian Marine National Facility）负责维护。