IMOS - SOOP Ocean Carbon Dioxide Data from RV Southern Surveyor voyage SS2012_V03 (Hobart-Hobart)

This data was collected in July 2012 by the IMOS Ship of Opportunity Underway CO2 Measurement research group on RV Southern Surveyor (IMOS platform code: VLHJ) voyage SS2012_V03.\n\nDeparted: \tHobart, TAS, July 11, 2012\nArrived: \tHobart, TAS, July 24, 2012\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.本数据集由综合海洋观测系统（Integrated Marine Observing System, IMOS）机遇航船走航CO₂测量研究组，于2012年在‘南方勘测者号’（RV Southern Surveyor，IMOS平台代码：VLHJ）的SS2012_V03航次中采集。 起航：塔斯马尼亚州霍巴特，2012年7月11日 抵港：塔斯马尼亚州霍巴特，2012年7月24日 CO₂系统概述： 表层海水二氧化碳逸度（fugacity of carbon dioxide, fCO₂）采用General Oceanics公司的自动化系统（型号8050；参考Pierrot等人2009年研究）进行测量。将海水喷入平衡舱，使顶空气体中的二氧化碳与海水达到气液平衡。顶空气体经热电冷凝器、纳菲恩（Nafion）干燥管输送后，通入Licor 7000型非色散红外气体分析仪，以测定干燥空气中的二氧化碳摩尔分数（XCO₂）。测量二氧化碳时会暂时中断气流，测量过程在大气压下进行。每约4小时分析一组覆盖海洋中预期二氧化碳浓度范围的4种二氧化碳标准气体，以校准气体分析仪。标准气体浓度采用WMO-X2007空气中二氧化碳摩尔分数基准。标准气体分析完成后，通过抽取船舶前桅杆进气口的洁净外部空气，测定干燥大气中的XCO₂。 海水采样及辅助数据： 海水采样口位于船舶船首约5.5米水深处。表层海水盐度由安装在CO₂系统旁的海鸟电子（Seabird Electronics）SBE21型热盐计测量。安装在采样口处的海鸟电子SBE 38型远程温度传感器用于测量海表温度（SST）。从采样口到CO₂系统的输水时长通常约为4分钟，输水过程中水温升高一般不超过0.6℃。热盐计的取水水源与CO₂系统相同，但输水管道在采样口处分流。对热盐计与平衡舱的温度记录进行比对后发现，两条输水管道的水温差通常小于0.1℃。热盐计的输水管道沿船舶外壁布设，水温通常高于平衡舱输水管道。热盐计输水管道的输水时长比平衡舱输水管道短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国家海洋设施（Australian Marine National Facility）负责维护。