the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 28 Mar 2025
Wildfires heat the middle troposphere over the Himalayas and Tibetan Plateau during the peak of fire season
Abstract. Atmospheric pollutions from biomass burning contribute to climatic and cryospheric changes by influencing solar radiation and the albedos of snow and ice surfaces in the Himalayas and Tibetan Plateau (HTP). We utilize long‐term MODIS fire products and ground‐based and satellite‐derived aerosol datasets to investigate the primary effect of wildfires from the south slopes of Himalayas on aerosol loading in the HTP. Results show consistent interannual and seasonal variation patterns, as well as statistically significant correlations, between AOD at 500 nm from AERONET stations (Pokhara, QOMS, Nam Co) and Himalayan fire counts. CALIPSO data reveal elevated smoke aerosol extinction coefficients at altitudes of 6~8 km (middle troposphere) in the southern HTP during the peak of fire season (March–April) in 2021. The intense wildfire activity in 2021 likely contributed to mid-tropospheric warming and alterations in the vertical temperature structure, as evidenced by a reduction in the absolute lapse rate, representing the rate of temperature decrease with altitude. This reduction was observed at QOMS, SETS, and Naqu stations when compared to 2022. SBDART simulations estimated increased heating rates (0.38~1.32 K day−1) and atmospheric warming (15.03~22.43 W m−2) in the mid-troposphere due to smoke aerosols. Such warming affects regional atmospheric stability and modulating surface temperatures. It is crucial to research into the heating/cooling processes induced by aerosols and their influence on the vertical temperature structure to comprehensively understand the impacts of aerosols on regional climate and the hydrological cycle.
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RC1: 'Comment on egusphere-2025-1172', Anonymous Referee #1, 07 May 2025
Wildfires have been a hot topic recently due to more frequent and stronger influences due to global warming. This study investigated the influences of atmospheric pollutions from wildfire biomass burning in the HTP. Multi-source data (including MODIS fire produce, CALIPSO, ground-based AERONET and so on) and SBDART simulations were used to test the influences of wildfires on temperature structures over the region. It is found that the wildfire activity in 2021 is possible to contribute mid-tropospheric warming and alterations in the vertical temperature structures. The manuscript is well organized and presented, and both the observations and simulations are well discussed. The paper could be considered for publication after addressing following specific comments.
General comments:
1. On the conclusion of the manuscript: This study compared the observations during wildfire active (2021) and less-active (2022) years, and indicated the influences due to wildfire from the differences. This is the main conclusion of the paper, while it should be presented more carefully due to the annual and seasonal differences on the atmospheric temperatures between the two years.
2. A large number of observations and retrievals of different kinds was used in this study to tackle the problems, and they have quite different accuracy. A brief discussion on the accuracy of different observations is suggested to be given (maybe in the supporting materials), because it will help the authors as well as the readers to better understood the reliability of the conclusions.
Specific comments:
3. For some of the figures, the colors of similar kinds were used, which may make the comparing confusion. For example, the red lines in Figure 8 can be hardly differed. Similar conditions were noticed in Figure 2 as well.
4. I suppose the word “fire counts” indicates the number of pixels detected as fires by MODIS product, and this could be different for general understanding of fire count. Please correct me if I am wrong, while the concept may be confusing for readers if I am right.
5. The vertical profiles of absorbing aerosol play an important role for the heating of aerosol radiative effects, Lu et al. (https://doi.org/10.1016/j.atmosres.2020.104891) gave an estimation of heating due to aerosol based on their numerical regression. Their estimations may be briefly compared with this study.
6. Figure 6 is difficult to be read, and suggested to be reorganized.
Citation: https://doi.org/10.5194/egusphere-2025-1172-RC1 - AC1: 'Reply on RC1', Chuanfeng Zhao, 12 Jun 2025
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RC2: 'Comment on egusphere-2025-1172', Anonymous Referee #2, 06 Jun 2025
Atmospheric pollutions from biomass burning contribute to climatic and cryospheric changes by influencing solar radiation and the albedos of snow and ice surfaces in the Himalayas and Tibetan Plateau (HTP). Wildfires are an important source of atmospheric pollutants in this region. This paper uses a variety of long-term satellite and ground-based data to investigate the primary effect of wildfires from the south slopes of Himalayas on aerosol loading. This can deepen our understanding of the climate effects of aerosols in the HTP region. The topic of the paper is well suited for Atmospheric Chemistry and Physics and the results are interesting. However, there are some important information is missing and several issues need to be revised. If these comments are addressed, I believe the paper should be accepted for publication.
- In abstract, Please add more quantitative results. The abstract should explicitly include the key finding of your manuscript. Currently, only some quantitative research results are given in lines 30-31 of the abstract.
- lines 113-115, Different types of biomass sources have different effects on atmospheric heating on the HTP, but this article does not discuss this.
- I recommended to supplement the information of observation instruments, observation elements, data efficiency, etc. of each station in Table S1.
- The analysis of Figure 2 in 3.1 is too simple. The long-term interannual variation characteristics and spatial distribution characteristics should be discussed and analyzed. In particular, the analysis of the differences in temporal and spatial distribution, such as lines 277-279, what are the reasons for such a large difference? Are there similar differences in satellite data?
- There are some formatting and spelling errors in the article, which need to be carefully revised. For example, line322.
- What are the reasons for the differences in the interannual variation characteristics of the extinction coefficients of different types of aerosols in Figure 4?
- In Figure 5, the vertical distributions of aerosol extinction coefficients and occurrence frequency profiles of different aerosol types from 2021 to 2023 are quite different. For example, the occurrence frequency of dust in 2022 is significantly lower than that in 2021, but the extinction coefficient in 2022 is higher. Similarly, the occurrence frequency of polluted dust is not much different in 2022 and 2023, but the difference in extinction coefficient is quite large. Similar differences in the vertical distribution of extinction coefficients and occurrence frequencies need to be analyzed in detail in the article.
- Conclusion and Perspective: It is recommended to focus on the conclusions in this section. The conclusions need to be condensed and summarized. The conclusions are not refined enough now. I recommended to put the Perspective in 3 Results and discussion.
Citation: https://doi.org/10.5194/egusphere-2025-1172-RC2 - AC2: 'Reply on RC2', Chuanfeng Zhao, 12 Jun 2025
Status: closed
-
RC1: 'Comment on egusphere-2025-1172', Anonymous Referee #1, 07 May 2025
Wildfires have been a hot topic recently due to more frequent and stronger influences due to global warming. This study investigated the influences of atmospheric pollutions from wildfire biomass burning in the HTP. Multi-source data (including MODIS fire produce, CALIPSO, ground-based AERONET and so on) and SBDART simulations were used to test the influences of wildfires on temperature structures over the region. It is found that the wildfire activity in 2021 is possible to contribute mid-tropospheric warming and alterations in the vertical temperature structures. The manuscript is well organized and presented, and both the observations and simulations are well discussed. The paper could be considered for publication after addressing following specific comments.
General comments:
1. On the conclusion of the manuscript: This study compared the observations during wildfire active (2021) and less-active (2022) years, and indicated the influences due to wildfire from the differences. This is the main conclusion of the paper, while it should be presented more carefully due to the annual and seasonal differences on the atmospheric temperatures between the two years.
2. A large number of observations and retrievals of different kinds was used in this study to tackle the problems, and they have quite different accuracy. A brief discussion on the accuracy of different observations is suggested to be given (maybe in the supporting materials), because it will help the authors as well as the readers to better understood the reliability of the conclusions.
Specific comments:
3. For some of the figures, the colors of similar kinds were used, which may make the comparing confusion. For example, the red lines in Figure 8 can be hardly differed. Similar conditions were noticed in Figure 2 as well.
4. I suppose the word “fire counts” indicates the number of pixels detected as fires by MODIS product, and this could be different for general understanding of fire count. Please correct me if I am wrong, while the concept may be confusing for readers if I am right.
5. The vertical profiles of absorbing aerosol play an important role for the heating of aerosol radiative effects, Lu et al. (https://doi.org/10.1016/j.atmosres.2020.104891) gave an estimation of heating due to aerosol based on their numerical regression. Their estimations may be briefly compared with this study.
6. Figure 6 is difficult to be read, and suggested to be reorganized.
Citation: https://doi.org/10.5194/egusphere-2025-1172-RC1 - AC1: 'Reply on RC1', Chuanfeng Zhao, 12 Jun 2025
-
RC2: 'Comment on egusphere-2025-1172', Anonymous Referee #2, 06 Jun 2025
Atmospheric pollutions from biomass burning contribute to climatic and cryospheric changes by influencing solar radiation and the albedos of snow and ice surfaces in the Himalayas and Tibetan Plateau (HTP). Wildfires are an important source of atmospheric pollutants in this region. This paper uses a variety of long-term satellite and ground-based data to investigate the primary effect of wildfires from the south slopes of Himalayas on aerosol loading. This can deepen our understanding of the climate effects of aerosols in the HTP region. The topic of the paper is well suited for Atmospheric Chemistry and Physics and the results are interesting. However, there are some important information is missing and several issues need to be revised. If these comments are addressed, I believe the paper should be accepted for publication.
- In abstract, Please add more quantitative results. The abstract should explicitly include the key finding of your manuscript. Currently, only some quantitative research results are given in lines 30-31 of the abstract.
- lines 113-115, Different types of biomass sources have different effects on atmospheric heating on the HTP, but this article does not discuss this.
- I recommended to supplement the information of observation instruments, observation elements, data efficiency, etc. of each station in Table S1.
- The analysis of Figure 2 in 3.1 is too simple. The long-term interannual variation characteristics and spatial distribution characteristics should be discussed and analyzed. In particular, the analysis of the differences in temporal and spatial distribution, such as lines 277-279, what are the reasons for such a large difference? Are there similar differences in satellite data?
- There are some formatting and spelling errors in the article, which need to be carefully revised. For example, line322.
- What are the reasons for the differences in the interannual variation characteristics of the extinction coefficients of different types of aerosols in Figure 4?
- In Figure 5, the vertical distributions of aerosol extinction coefficients and occurrence frequency profiles of different aerosol types from 2021 to 2023 are quite different. For example, the occurrence frequency of dust in 2022 is significantly lower than that in 2021, but the extinction coefficient in 2022 is higher. Similarly, the occurrence frequency of polluted dust is not much different in 2022 and 2023, but the difference in extinction coefficient is quite large. Similar differences in the vertical distribution of extinction coefficients and occurrence frequencies need to be analyzed in detail in the article.
- Conclusion and Perspective: It is recommended to focus on the conclusions in this section. The conclusions need to be condensed and summarized. The conclusions are not refined enough now. I recommended to put the Perspective in 3 Results and discussion.
Citation: https://doi.org/10.5194/egusphere-2025-1172-RC2 - AC2: 'Reply on RC2', Chuanfeng Zhao, 12 Jun 2025
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