ACT-America: L2 In Situ CO2, CO, and CH4 Concentrations from Towers, Eastern USA

This dataset provides atmospheric carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4) concentrations as measured on a network of instrumented communications towers operated by the Atmospheric Carbon and Transport-America (ACT-America) project. ACT-America's mission spans five years and includes five 6-week intensive field campaigns covering all 4 seasons and 3 regions of the central and eastern United States. Tower-based measurements began in early 2015 and are continuously collecting CO2, CO, and CH4 data to characterize ground-level (>100 m) carbon background conditions to support the periodic airborne measurement campaigns and transport modeling conducted by ACT-America. The towers are instrumented with infrared cavity ring-down spectrometer systems (CRDS; Picarro Inc.). Data are reported for the highest sampling port on each tower. The averaging interval standard deviation and uncertainty derived from periodic flask sample to in-situ measurement comparisons are provided. Complete tower location, elevation, instrument height, and date/time information are also provided.

本数据集收录由大气碳与运输-美国（Atmospheric Carbon and Transport-America, ACT-America）项目运营的仪器化通信塔网所测得的大气二氧化碳（CO₂）、一氧化碳（CO）及甲烷（CH₄）浓度数据。ACT-America项目的执行周期为五年，涵盖五次为期六周的高密度野外攻坚科考活动，覆盖美国中东部的3个区域及全年四个季节。基于该塔网的观测工作始于2015年初，目前仍在持续采集CO₂、CO及CH₄数据，以表征离地高度大于100米处的碳本底状况，为ACT-America项目开展的周期性航空观测科考与大气传输模拟研究提供支撑。所有观测塔均搭载红外腔环衰光谱仪系统（infrared cavity ring-down spectrometer systems, CRDS；Picarro公司）。数据集提供每座观测塔最高采样端口的观测数据，同时包含由周期性气袋采样与原位测量比对得到的平均间隔标准差及不确定度数据。此外还完整收录各观测塔的位置、海拔高度、仪器安装高度及日期/时间信息。