IMOS - Ships of Opportunity - Ocean Carbon Dioxide Data from RV Southern Surveyor voyage SS2011_V02 (Brisbane-Auckland)

This data was collected in May/June 2011 by the IMOS Ship of Opportunity Underway CO2 Measurement research group on RV Southern Surveyor (IMOS platform code: VLHJ) voyage SS2011_V02.Departed:     Brisbane, QLD, May 13, 2011Arrived:     Auckland, NZ, Jun 04, 2011CO2 System Overview:The 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. Seawater intake and ancillary data:The 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. Meteorological 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船舶走航CO₂测量研究小组于2011年5至6月期间，在研究船“南方探索者号”（RV Southern Surveyor，IMOS平台代码：VLHJ）的SS2011_V02航次中采集完成。
启航港：澳大利亚昆士兰州布里斯班，2011年5月13日
抵港：新西兰奥克兰，2011年6月4日

CO₂系统概述：本研究采用General Oceanics Inc.生产的全自动CO₂测量系统（型号8050；参考Pierrot等2009年研究成果），测定表层海水二氧化碳逸度（fCO₂）。具体检测流程如下：将表层海水喷入气液平衡舱，使顶空气体中的CO₂与海水充分达到溶解平衡；随后将顶空气体泵送至热电冷凝器，经纳菲隆干燥管去除水汽后，通入Licor 7000型非色散红外气体分析仪，以测量干燥空气的CO₂摩尔分数（XCO₂）。CO₂浓度测量过程中会暂时中断气流，且所有测量均在大气压条件下进行。每间隔约4小时，便会分析一套覆盖海洋环境预期CO₂浓度范围的4种标准CO₂气体，用于校准气体分析仪。标准气体的浓度基准采用WMO-X2007空气中CO₂摩尔分数尺度。完成标准气体校准后，通过船舶前桅的进气口抽取洁净外界空气，以测定大气干燥XCO₂数值。

海水取水与辅助观测数据：海水取水口位于船舶船首约5.5米深度处。海面盐度通过紧邻CO₂测量系统的热盐计（Seabird Electronics SBE21）测定。取水口处搭载的远程温度传感器（Seabird Electronics SBE38）用于测量海面水温（SST）。取水口至CO₂测量系统的输水时长通常约为4分钟，期间海水升温幅度一般不超过0.6℃。热盐计的供水水源与CO₂测量系统一致，但在取水口后输水管路发生分支。对比热盐计与平衡舱的温度记录可知，两条输水管路的水温差通常小于0.1℃。热盐计的输水管路沿船舶外部铺设，其水温通常高于平衡舱输水管路。热盐计输水管路的输水时长比平衡舱管路快2.5分钟。

气象数据、海水盐度、海面水温、船舶位置与时间均取自船舶日志系统。上述观测参数及对应数据质量均由澳大利亚海洋国家设施（Australian Marine National Facility）负责维护。