Temporal Variation of NO2 and HCHO Vertical Profiles Derived from MAX-DOAS Observation in Summer at a Rural Site of the North China Plain and Ozone Production in Relation to HCHO/NO2 Ratio
Temporal Variation of NO2 and HCHO Vertical Profiles Derived from MAX-DOAS Observation in Summer at a Rural Site of the North China Plain and Ozone Production in Relation to HCHO/NO2 Ratio
复制标题
华北平原农村夏季MAX-DOAS观测得到的NO2和HCHO垂直剖面随时间变化及臭氧产生量与HCHO/NO2比值的关系
DOI：
10.3390/atmos13060860
复制
发表时间：
2022-06-01
期刊：
影响因子：
2.9
通讯作者：
Xu, Xiaobin
中科院分区：
文献类型：
--
作者：
Cheng, Siyang;Jin, Junli;Xu, Xiaobin
We performed a comprehensive and intensive field experiment including ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurement at Raoyang (115 degrees 44' E, 38 degrees 14' N; 20 m altitude) in summer (13 June-20 August) 2014. The NO2 and HCHO profiles retrieved by MAX-DOAS take on different vertical distribution shapes, with the former declining with the increasing altitude and the latter having an elevated layer. The average levels of vertical column densities (VCDs) and near-surface volume mixing ratios (VMRs) were 1.02 +/- 0.51 x 10(16) molec.cm(-2) and 3.23 +/- 2.70 ppb for NO2 and 2.32 +/- 0.56 x 10(16) molec.cm(-2) and 5.62 +/- 2.11 ppb for HCHO, respectively. The NO2 and HCHO levels are closely connected with meteorological conditions, with the larger NO2 VCDs being associated with lower temperature, higher relative humidity (RH) and lower planetary boundary layer height (PBLH). With respect to the diurnal variations of vertical distribution, the NO2 in the residual layer gradually disappeared from 1.2 km height to the surface during the period of 7:00-11:00 Beijing time (BJ), and the near-surface NO2 had larger VMRs in the early morning and evening than in the later morning and afternoon. An elevated HCHO layer was observed to occur persistently with the lifted layer height rising from similar to 0.5 km to similar to 1.0 km before 10:00 BJ; the near-surface HCHO VMRs gradually increased and peaked around 10:00 BJ. The ratios of HCHO to NO2 (RHCHO-NO2) were generally larger than two in the boundary layer from 11:00 BJ until 19:00 BJ, the time period when ozone photochemistry was most active. Thus, ozone (O-3) production was mainly in the NOR-limited regime during the observation campaign, which was closely related to relatively high temperatures and low RH. The O-3 production regimes also changed with the wind's direction. These results are significant to reveal the formation mechanism of O-3 pollution and develop strategies for controlling the O-3 photochemical pollution over the North China Plain.
