IMOS - SOOP Ocean Carbon Dioxide Data from MV L'Astrolabe voyage AL1011R0 (Hobart-Dumont d'Urville station)

This data was collected in October 2010 by the IMOS Ship of Opportunity Underway CO2 Measurement research group on MV L'Astrolabe (IMOS platform code: FHZI) voyage AL1011R0.\n\nDeparted: Hobart Australia, October 21, 2010\nArrived: \t Dumont d'Urville station, Antarctica, October 27, 2010\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 (Table 1) 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\nThe seawater intake is at about 3m depth in the bow of the ship. 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 bow thruster space near the intake. The travel time between the intake and CO2 system is typically about 50 seconds with warming usually less than 0.4ºC. The thermosalinograph water is from the same intake and supply line. Meteorological data, salinity, SST, and ships position and time are taken from the ship’s logging system. The salinity values measured by the SBE21 were checked against discrete bottle samples collected on the voyage.\n\nMeteorological data, salinity, SST, and ships position and time are taken from the ships logging system.

本数据集由综合海洋观测系统（Integrated Marine Observing System，IMOS）的机遇船舶走航CO₂测量研究小组，于2010年10月在“星盘号”（MV L'Astrolabe，IMOS平台代码：FHZI）的AL1011R0航次中采集完成。

起航：澳大利亚霍巴特，2010年10月21日
抵达：南极洲迪蒙·迪尔维尔站，2010年10月27日

CO₂系统概述：
表层海水二氧化碳逸度（fCO₂）采用通用海洋公司（General Oceanics Inc.）的自动化测量系统（型号8050；Pierrot等，2009）进行测定。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、纳菲恩干燥管输送后，通入LI-COR 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（CO2 mole fraction，XCO₂）。二氧化碳测量在常压下进行，测量期间会临时中断气流。每约3小时会对覆盖海洋典型二氧化碳浓度范围的4组二氧化碳标准气体（表1）进行分析，以校准气体分析仪。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，测定干燥大气中的XCO₂。

海水采样口位于船舶船艏约3米水深处。位于采样口的海鸟电子（Seabird Electronics）SBE38型远程温度传感器，用于测定海表温度（Sea Surface Temperature，SST）。海表盐度通过安装在采样口附近船艏推力器舱内的海鸟电子SBE21型热盐仪测定。采样口至CO₂分析系统的输水时长通常约为50秒，输水过程中海水温升一般不超过0.4℃。热盐仪的采样水源与CO₂分析系统取自同一采样口及输水管道。气象数据、盐度、SST、船舶位置及时间信息均取自船舶日志系统。研究人员将SBE21型热盐仪测得的盐度值，与本航次采集的离散采水器样本进行了盐度比对校正。

气象数据、盐度、SST、船舶位置及时间信息均取自船舶日志系统。