Reply on RC1

report: C ontrasting elevation dependent light and carbon lessons from in measurements from highly (Title: Measurement report: The first in-situ PM 1 chemical measurements at the steep slope from highly polluted Sichuan Basin to pristine Tibetan Plateau: light absorption of carbonaceous aerosols, and source and origin impacts, ID: acp-2022-241). the quality of our manuscript. corresponding conducted in the new manuscript. responses to the in detail follows.

Thank you for your positive comments on our manuscript (Title: Measurement report: The first in-situ PM 1 chemical measurements at the steep slope from highly polluted Sichuan Basin to pristine Tibetan Plateau: light absorption of carbonaceous aerosols, and source and origin impacts, ID: acp-2022-241). Your constructive suggestions are very valuable for improving the quality of our manuscript. The corresponding revisions will be conducted in the new manuscript. The responses to the comments are given in detail as follows.
Major Comments: Using Equation (5) to separate total aerosol absorption into EC and BrC absorption is an objective and effective method. But the shortcomings of the method should be kept in mind when analyzing and discussing the results. For example, the method does not consider the absorption of mineral dust (or fine soils), which accounts for very small percentage for most urban sites but might account for a large proportion of total aerosols for some other sites. Previous studies have revealed that the mineral dust is an important species of the atmospheric aerosols over the Tibetan Plateau (e.g., Zhang et al., 2021). Besides, assuming AAE of EC as 1 does not take into the aging of EC.
Response: Thank you for your suggestions and providing the important recent study on mineral dust over the TP (Zhang et al., 2021). As you said, the main shortcoming of the separation of total aerosol absorption into EC and BrC (Eq. 5) is lack of considering the mineral dust impacts. According to the recent study of Zhang et al. (2021), mineral dust may be an important species of the atmospheric aerosols over the Tibetan Plateau. However, the study region is located at the eastern slope of TP during our campaign, which is more easily affected by anthropogenic sources from heavy polluted Sichuan Basin than natural sources such as mineral dust as compared to the north areas close to Taklimakan and Gobi Deserts. One main aim of this study is to reveal the gradient distributions of aerosol optical properties from the pollution Sichuan Basin to eastern TP, and thus the impact of the shortcoming may be less when studying the spatial heterogeneity of aerosol optical properties at relatively small spatial scale. In addition, AAE of EC is assumed as 1, and the aging of EC did not take when separating the total aerosol absorption into EC and BrC (Eq. 5) in our study. The above explanations will be added and the recent study will be cited in the revised manuscript. 405-980 nm and 405-445 nm for each sample. The explanation will be added to the revised manuscript.

Section 2.5: Which version of the EPA PMF model was used in the study?
Response: Thank you for catching that. EPA PMF 5.0 was used to apportion the sources in this study, which will be revised in the new manuscript. Response: Thank you for your reminder. In Table 1, Chengdu, Sanbacun, Wenchuan, Lixian, Maerkang and Hongyuan are abbreviated as CD, SBC, WC, LX, MEK and HY, respectively. The definition will be given in the table caption in the revised manuscript.
Page 12 and Figure 7: The physical meaning of the parameter (radiative forcing of BrC relative to EC) is recommended to be further discussed. Were the nighttime samples used when calculating this parameter?
Response: Thank you for your suggestions. The nighttime samples were excluded when calculating the radiative forcing of BrC relative to EC. The parameter (radiative forcing of BrC relative to EC) reflects light absorption strength of BrC at the shorter wavelengths as compared to that of EC aerosols at the whole wavelengths. The much higher f values indicated that radiative forcing of BrC aerosols is much stronger for the similar EC radiate forcing, and thus this parameter can be used to better understand the radiative forcing of secondary aerosols relative to primary aerosols at a specific location. The above discussion will be added to Page 12 of the revised manuscript.