Tropospheric HOx: Sources, Sinks, and Exchange in the Planetary Boundary Layer

该项目的重点是研究OH（羟基自由基）和HO2（氢氧自由基）（合称为HOx）对其源和汇的依赖，并检查观测和模型之间的差异。对OH和HO2的测量揭示了对大气氧化过程以及气象和污染对这些过程的影响的新见解。虽然在自由对流层中，OH和HO2之间的快速循环似乎得到了充分的描述，但观测到的OH和HO2往往与模式计算不一致。用于HOx测量的仪器是基于FAGE技术（在低压下激光诱导的OH荧光检测）。该仪器将部署在密歇根州的PROPHET（氧化剂研究计划：光化学、排放和运输）站点的密集测量期间。将进一步开展改进仪器校准和确定可能干扰的工作。总OH损失率也将使用一种新的方法来测量。HOx通量将使用涡流相关技术从塔上测量。

The focus of this project is to study the dependence of OH (hydroxyl radical) and HO2 (hydroperoxy radical), together known as HOx, on their sources and sinks and to examine discrepancies between observations and models. Measurements of OH and HO2 are revealing new insight into atmospheric oxidation processes and the influences of meteorology and pollution on those processes. While fast cycling between OH and HO2 appears to be adequately described for the free troposphere, the observed OH and HO2 often cannot be reconciled with model calculations. The instrument that will be used for HOx measurements is based on the FAGE technique (laser-induced fluorescence detection of OH at low pressure). The instrument will be deployed during intensive measurement periods at the PROPHET (Program for Research on Oxidants: Photochemistry, Emissions and Transport) site in Michigan. Further work will be carried out on improving instrument calibration and determining possible interferences. The total OH loss rate will also be measured using a novel approach. The HOx flux will be measured using eddy correlation techniques from a tower.