Atmospheric Methane Mixing Ratios--The NOAA/CMDL Global Cooperative Air Sampling Network, 1983-1993

This data base presents atmospheric methane (CH4) mixing ratios from flask air samples collected over the period 1983-1993 by the National Oceanic and Atmospheric Administration, Climate Monitoring and Diagnostics Laboratory's (NOAA/CMDL's) global cooperative air sampling network. Air samples were collected approximately once per week at 44 fixed sites (37 of which were still active at the end of 1993). Samples were also collected at 5 degree latitude intervals along shipboard cruise tracks in the Pacific Ocean between North America and New Zealand (or Australia) and at 3 degree latitude intervals along cruise tracks in the South China Sea between Singapore and Hong Kong. The shipboard measurements were made approximately every 3 weeks per latitude zone by each of two ships in the Pacific Ocean and approximately once every week per latitude zone in the South China Sea. All samples were analyzed for CH4 at the NOAA/CMDL laboratory in Boulder, Colorado, by gas chromatography with flame ionization detection, and each aliquot was referenced to the NOAA/CMDL methane standard scale. In addition to providing the complete set of atmospheric CH4 measurements from flask air samples collected at the NOAA/CMDL network sites, this data base also includes files which list monthly mean mixing ratios derived from the individual flask air measurements. These monthly summary data are available for 35 of the fixed sites and 21 of the shipboard sampling sites. For access to the data files, click this link to the CDIAC data transition website: http://cdiac.ess-dive.lbl.gov/ndps/db1008.html

本数据库收录了美国国家海洋和大气管理局气候监测与诊断实验室（NOAA/CMDL）全球合作空气采样网络在1983-1993年间采集的瓶采空气样品的大气甲烷（CH4）混合比数据。该网络在44个固定采样点每周采集约1次空气样品，其中37个站点在1993年末仍处于运行状态。此外，研究团队还在北美至新西兰（或澳大利亚）的太平洋船舶巡航航线上以5度纬度间隔布设采样点，以及在新加坡至香港的南海巡航航线上以3度纬度间隔布设采样点采集空气样品。太平洋航线由两艘科考船分别执行采样任务，每个纬度带约每3周完成一次测量；南海航线则约每周完成一次对应纬度带的采样工作。所有样品均送至美国科罗拉多州博尔德市的NOAA/CMDL实验室，采用带火焰离子化检测器的气相色谱法开展甲烷浓度分析，且每份分装样品均以NOAA/CMDL甲烷标准量表为参照进行校准。本数据库除收录NOAA/CMDL网络固定站点采集的全部瓶采大气甲烷测量数据外，还包含基于单份瓶采空气样品测量结果计算得到的月平均混合比数据文件。上述月度汇总数据可从35个固定采样点与21个船舶采样点获取。如需获取数据文件，请点击此链接跳转至CDIAC数据过渡网站：http://cdiac.ess-dive.lbl.gov/ndps/db1008.html