IMOS - Ships of Opportunity - Ocean Carbon Dioxide Data from RV Aurora Australis voyage AA1112V3 (Hobart-Fremantle)

This data was collected in January/February 2012 by the IMOS Ship of Opportunity Underway CO2 Measurement research group on RV Aurora Australis (IMOS platform code: VNAA) voyage AA1112V3.Departed:     Hobart, Tasmania, January 05, 2012Arrived: Fremantle, Western Australia, February 12, 2012CO2 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 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. Seawater intake and ancillary data:The seawater intake is at about 6 m depth. 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 oceanographic lab next to the pCO2 system. The travel time between the intake and CO2 system is typically about 70 seconds with warming usually less than 0.7ºC in cold waters near freezing. 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.

本数据集由IMOS机会船航行中CO₂测量研究小组于2012年1-2月在RV Aurora Australis号科考船（IMOS平台代码：VNAA）的AA1112V3航次期间采集。

出发地：塔斯马尼亚州霍巴特，2012年1月5日
到达地：西澳大利亚州弗里曼特尔，2012年2月12日

CO₂系统概述：
表层海水中的二氧化碳逸度（fCO₂）采用General Oceanics Inc.的自动化系统（型号8050；Pierrot等人，2009）进行测量。海水被喷入平衡室，顶空气体中的CO₂与海水达到平衡。顶空气体依次通过热电冷凝器和Nafion干燥管，随后进入Licor 7000非分散红外气体分析仪，用于测量干燥空气中的CO₂摩尔分数（XCO₂）。CO₂测量时气体流动暂时停止，测量在大气压下进行。每约3小时分析一组涵盖海洋预期CO₂值范围的四种CO₂标准气，以校准气体分析仪。标准气分析后，通过抽取船首桅杆进气口的清洁室外空气，测量大气干燥XCO₂。

海水取水口及辅助数据：
海水取水口深度约为6米。取水口处安装有远程温度传感器（Seabird Electronics SBE38），用于测量海面温度（SST）。海面盐度采用安装在海洋学实验室中二氧化碳分压（pCO₂）系统旁的温盐仪（Seabird Electronics SBE21）测量。取水口到CO₂系统的传输时间通常约为70秒，在接近冰点的冷水域中，水温升高通常小于0.7℃。温盐仪所用海水来自同一取水口和供水管线。

气象数据、盐度、海面温度、船舶位置及时间均取自船舶日志系统。