Travis K R, Judd L M, Crawford J H, Chen Gao, Szykman James, Whitehill Andrew, Valin Lukas C, Spinei Elena, Janz Scott, Nowlan Caroline R, Kwon Hyeong-Ahn, Fried Alan, Walega James
NASA Langley Research Center, Hampton, VA, USA.
Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC, USA.
J Geophys Res Atmos. 2022 Jul 16;127(13):e2022JD036638. doi: 10.1029/2022JD036638.
Formaldehyde column density (ΩHCHO) showed a potentially useful correlation with surface ozone during the LISTOS campaign on Long Island Sound and the KORUS-AQ campaign in Seoul, South Korea. This builds on previous work that identified this relationship from in situ aircraft observations with similar findings for ground-based and airborne remote sensing of ΩHCHO. In the Long Island Sound region, ΩHCHO and surface ozone exhibited strong temporal ( = 0.66) and spatial ( = 0.73) correlation. The temporal variability in ΩHCHO (∼1 Dobson units [DU]) was larger than the range in the spatial average (∼0.1 DU). The spatial average is most useful for informing ozone monitoring strategies, demonstrating the challenge in using ΩHCHO satellite data sets for this purpose. In Seoul, high levels of NO resulted in O better correlating with ΩHCHO than surface ozone due to titration effects. The ΩHCHO-O relationship may therefore reflect the sum of surface ozone and related photochemical oxidants, relevant to air quality standards set to regulate this quantity such as the U.S. EPA National Ambient Air Quality Standard (NAAQS). The relationship of ΩHCHO to O shifted in Seoul during the campaign demonstrating the need to evaluate this relationship over longer time periods. With sufficient precision in future satellite retrievals, ΩHCHO observations could be useful for evaluating the adequacy of surface air quality monitoring strategies.
在长岛海峡的 LISTOS 活动以及韩国首尔的 KORUS-AQ 活动期间，甲醛柱密度（ΩHCHO）与地表臭氧显示出潜在的有用相关性。这是基于之前的工作，该工作从原位飞机观测中确定了这种关系，地面和机载遥感对 ΩHCHO 的观测也有类似发现。在长岛海峡地区，ΩHCHO 和地表臭氧表现出很强的时间相关性（= 0.66）和空间相关性（= 0.73）。ΩHCHO 的时间变异性（约 1 多布森单位[DU]）大于空间平均值的范围（约 0.1 DU）。空间平均值对于指导臭氧监测策略最为有用，这表明为此目的使用 ΩHCHO 卫星数据集存在挑战。在首尔，由于滴定效应，高浓度的 NO 导致 O 与 ΩHCHO 的相关性比与地表臭氧的相关性更好。因此，ΩHCHO - O 的关系可能反映了地表臭氧和相关光化学氧化剂的总和，这与为监管该数量而设定的空气质量标准相关，例如美国环境保护局国家环境空气质量标准（NAAQS）。活动期间，首尔的 ΩHCHO 与 O 的关系发生了变化，这表明需要在更长的时间段内评估这种关系。如果未来卫星反演具有足够的精度，ΩHCHO 观测可用于评估地表空气质量监测策略的充分性。
