The manuscript addresses an important environmental issue, vertical formation mechanism of nitrates in Asian megacities. It is overall well written, providing important progress through vertically continuous observations and comprehensive data analysis. My specific comments are as follows:

1. It's recommended to change the title from "Synergistic Lidar - Aircraft Observations and Process - Based Analysis" to "Integrated Lidar - Aircraft Observations and Process Analysis".
2. In the Data and Methods section, include more details about the machine learning model (such as algorithm name, input variables, R² value for validation accuracy) and cite relevant studies.
3. Line 92，please add a bit more information about Gaussian smoothing.
4. Line103，explain why 1064 nm wavelength was selected.
5. Line117，please add the grid resolution of CAMS data.
6. Line 140，The "Toxic Pollution" category (>250 μg/m³) mentioned in the text seems to have no data support in Fig. 1. Perhaps either delete it or merge it into other categories.
7. Line 140-143，Peak height correlates with the boundary layer structure. Does the peak at 900-m reach the top of the inversion layer?
8. Figure 5: too much information. Please split and simplify the figure.
9. Figure 8: Please add vertical profiles of AOC and NO₂/O₃ to support the conclusion that "high AOC promotes NO₂ to nitrate, not O₃."
10. Figure 1,4 A bit too many panels. The authors could move the panels f - k to the supplementary materials.
11. The number of equations seems odd. Please double check.
12. Tense check: Please use past tense for the results discussion.
13. Make sure all citations are listed. For example, Guan et al., 2024 is cited in the introduction but not in the references.

This work comprehensively investigated the vertical distribution, seasonal variation, and formation mechanisms of nitrate pollution at different altitudes in urban Beijing, and thus is important. There are some comments which require to be addressed before it can be accepted.

1. The title showed aircraft observation, however there is no any description in the main text. Add necessary related description or remove the aircraft from the title.
2. Line 20, provide the specific height or height range for “the boundary layer top”.
3. Line 23, what policy suggestion for the “actionable insights”?
4. Line 49, “Therefore, the nitrate formation processes in the atmosphere are complex and challenging to elaborate” can be moved to the end of this paragraph.
5. Line 56, for the “Despite a global decrease in nitrate radicals (NO3)”, is there any evidence and reference?
6. Line 69, For the description “nitrate concentrations tend to increase with altitude”, please supplement the condition of this phenomenon, such as within boundary layer or lower boundary layer.
7. Line 80, add “and” before “coefficient analyses”.
8. Line 81, “managing nitrate pollution” can be “mitigating nitrate pollution”.
9. Line 112, pay attention to the subscript for NO2.
10. Line 95-96, how about the consistence between the ACSM measurements and the retrieval data at the lowest level? Simplify describe the comparison result.
11. Line 115-117, how about the consistence between the ground NO2 measurements at the Beijing Olympic Sports Center and the ground-level data from CAMS?
12. Line 170, it needs to clarify that NO2 are finally converted into nitric acid, nitrate, and organic nitrates.
13. Line 171-172, show the correlation coefficient for the “weak correlation”.
14. Line 190-192, show the correlation coefficients and the p values.
15. Line 201-202, “the negative correlation between RH and nitrate” cannot conclude the nitrate decomposition at high humidity condition. Correct the explanation.
16. Fig. 2, it seems that the extremely polluted cases in Fig. 6, Fig. 8, and Fig. 9 were not clearly shown in Fig. 2. Double check or explain it.
17. Fig. 5, Thermodynamics processes generally also include the thermal decomposition of particulate nitrate. In addition, there may be some problem in the color of the correlation coefficient for TKE and w, because very low values also show red or light red color.
18. Fig. 6, show the p values for the linear correlations in Fig. 6 a-h. Same suggestion for Fig. 8 and Fig. 9.