IMOS - SOOP Ocean Carbon Dioxide Data from RV Southern Surveyor voyage SS2011_T04 (Fremantle-Hobart)

This data was collected in November 2011 by the IMOS Ship of Opportunity Underway CO2 Measurement research group on RV Southern Surveyor (IMOS platform code: VLHJ) voyage SS2011_T04.\n\nDeparted: \tFremantle, WA, Nov 10, 2011\nArrived: \tHobart, TAS, Nov 20, 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 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船舶机会航次在线CO₂测量研究小组于2011年11月，在“南方探索者号”（RV Southern Surveyor，IMOS平台代码：VLHJ）的SS2011_T04航次中采集。

起航： 西澳大利亚州弗里曼特尔（Fremantle, WA），2011年11月10日
抵达： 塔斯马尼亚州霍巴特（Hobart, TAS），2011年11月20日

CO₂测量系统概览：
表层海水二氧化碳分压（fugacity of carbon dioxide，fCO₂）采用General Oceanics Inc.自动化系统（型号8050；Pierrot等，2009）进行测定。具体流程为：将海水喷入平衡舱，顶空气体中的CO₂与海水达到气液平衡。随后顶空气体经热电冷凝器、纳菲昂干燥管（nafion drying tube），之后流经Licor 7000型非色散红外气体分析仪，以测定干燥空气中的CO₂摩尔分数（XCO₂）。CO₂测量过程中会暂时中断气流，且所有测量均在大气压下完成。每约4小时会分析一组覆盖海洋预期CO₂浓度范围的4种CO₂标准气体，用于校准气体分析仪。标准气体的浓度采用WMO-X2007空气中CO₂摩尔分数量表。标准气体测量完成后，通过船舶前桅的进气口抽取清洁室外空气，以测定大气干燥态XCO₂。

海水取水口与辅助数据：
海水取水口位于船舶船艏约5.5米水深处。紧邻CO₂系统处安装有热盐深仪（thermosalinograph，Seabird Electronics SBE21），用于测量海表盐度。取水口处搭载远程温度传感器（Seabird Electronics SBE 38），用于测定海表温度（Sea Surface Temperature，SST）。取水口至CO₂系统的输水时长通常约为4分钟，期间水温升高幅度通常小于0.6℃。热盐深仪的取水水源与CO₂系统同源，但输水管道在取水口后即分流。对热盐深仪与平衡舱的温度记录对比显示，两条输水管道的温差通常小于0.1℃。热盐深仪的输水管道沿船舶外部铺设，其水温通常高于平衡舱输水管道。热盐深仪的输水时长较平衡舱短2.5分钟。

气象数据、盐度、海表温度、船舶位置与时间数据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。