The relative contribution (BC_sfb/BC_tr ratio) of black carbon (BC) from traffic and solid fuel burning were evaluated in different microenvironments. We used a mobile platform to measure concentrations of BC and Delta-C (DC) in four microenvironments (diesel plume, urban freeway, urban street, and rural freeway). A total of 38,661 measurements of BC and DC concentrations each averaged over 5 s (in winter 2018 and fall 2020) were used to evaluate the BC_sfb/BC_tr ratio. Measurements were divided into three sampling campaigns (2018 nonholiday, 2020 nonholiday, and 2020 holiday) to evaluate holiday and ambient temperature impacts on the BC_sfb/BC_tr ratio. There was a large reduction of BC but not DC concentrations during holidays. We found elevated BC_sfb/BC_tr ratios in winter 2018 and fall 2020 that can be related to residential heating and cooking, respectively. A strong linear relationship (R² = 0.89, p < 0.05) between DC/BC ratios and BC_sfb/BC_tr ratios in the four microenvironments is shown as evidence that the DC/BC ratio is an indicator for solid fuel burning emissions and is independent of sampling technique and location. The relationship between DC/BC and BC_sfb/BC_tr ratios can be further used to quantitatively discern BC contributions from traffic and solid fuel burning emissions regardless of the type of microenvironments.

中文翻译：

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微环境中碳质气溶胶的移动测量以识别交通和固体燃料燃烧的贡献

在不同的微环境中评估了来自交通和固体燃料燃烧的黑碳 (BC)的相对贡献（BC _sfb / BC _tr比率）。我们使用移动平台测量四种微环境（柴油烟羽、城市高速公路、城市街道和农村高速公路）中 BC 和 Delta-C (DC) 的浓度。总共 38,661 次 BC 和 DC 浓度测量值均在 5 秒内（2018 年冬季和 2020 年秋季）平均用于评估 BC _sfb / BC _tr比率。测量分为三个抽样活动（2018 年非节假日、2020 年非节假日和 2020 年节假日），以评估节假日和环境温度对 BC _sfb / BC _{tr 的影响}比率。在假期期间，BC 浓度大幅降低，但 DC 浓度没有大幅降低。我们发现2018 年冬季和 2020 年秋季BC _sfb / BC _tr比率升高，这可能分别与住宅供暖和烹饪有关。四个微环境中DC/BC 比率和 BC _sfb /BC _tr比率之间的强线性关系 ( R ² = 0.89, p < 0.05)被证明是 DC/BC 比率是固体燃料燃烧排放的指标的证据，并且是独立于采样技术和位置。DC/BC与BC _sfb /BC _tr的关系 比率可进一步用于定量识别交通和固体燃料燃烧排放的 BC 贡献，而不管微环境的类型如何。