This study presents detailed investigations on the fluorescence characteristics, absorption properties, and radiative effects of water-soluble organic carbon in seasonal snow across northeastern China, which plays a profound effect on snow albedo and solar radiation balance. They found that the WSOC mainly has mixed origins, including anthropogenic activity, microbial activity, and soil. The albedo reduction by WSOC (average concentration of 3.6 μg g^-1) was about 50% of the albedo reduction due to BC (average concentration of 0.6 μg g^-1) in the UV-vis (Ultraviolet-visible) band, and the radiative forcing was 3.8 (0.8) W m^-2 in old (fresh) snow, which was equal to 19% (17%) of the radiative forcing by BC. The manuscript is generally well-written and presents comprehensive high-quality data analysis, which will be of interest to the community. I believe the manuscript can be accepted after addressing the following comments.

1. In page 2, Line 12, more references should be given, especially for organic carbon and biota aerosols on the principal LAPs in snow.
2. I suggested that the first paragraph should be reconstructed; the author should primarily define LAPs and then illustrate their effects on snow albedo reduction.
3. Page 3, line 8-12, the sentence should be divided into separate sentences. Moreover, Page 3, line 16, references also should be provided after illustrating new investigations.
4. Page 3, line 18-29, Atmospheric particulate deposition is an important source of organic matter in snow. The author should expound the application and progress of EEM method in atmospheric particulate matter research. Such as chromophores type identification, origin analysis, atmospheric chemical processes.
5. Page 6, line 11-12, the TSI technique was not found in the literature of Shi (2020) and Wang (2014b), please cite with Wang et al (2020), and also provide in the reference list.
6. Page 8, line 22-25, the sentence is too long; please divide it into compact sentences. Also carefully revised all other long sentences throughout the manuscript.
7. The authors should carefully revise the number of significant digits (e.g. Page 10, line 16-17).
8. Page 10, line 25, the year of the citation should be given in brackets.
9. Page 11, line 2-4, the sentence should be divided into individual sentences.
10. Reference to previous studies to explain what HULIS-1 and HULIS-2 are, and clarify the advantages and disadvantages.
11. In Figure 3f-g, there is a similar contribution to HULIS-2, but the explanation is still unclear. Please explain.
12. It’s better to provide the equations on radiative forcing than that only cited from other references in section 2.4.
13. Compared with the integrated relative absorption from 280 to 400 nm in Fig. 7a, what does Fig. 7b used for? Please explain.
14. In the conclusion section from Page 23, line 20-Page 24, line 27, parts of the contents were duplicated with the result section. Suggested reconstructed.

The manuscript discussed the fluorescence characteristics, absorption properties, and radiative effects of WSOC based on 34 snow samples collected from sites in northeastern China. Given that the fluorescence characteristics, absorption properties, and radiative effects of WSOC in snow samples in northeastern China are not addressed in the literature, the work therefore is novel and would add useful information to the climate effect of WSOC. There are some issues and comments that need to be considered before publication:

Specific comments:

1. Page 3, Line 2: “the majority of which is water soluble organic carbon (WSOC).”, Please provide references.
2. Page 3, Line 2-6, Some more important information on WSOC should be involved in the Introduction.
3. Page 3, Line 19: Please provide the corresponding references.
4. Page 4, Line 10-11: “34 samples of seasonal snow collected in December 2020 and January 2021”, repeated information which has been mentioned in Line 20.
5. Page 5, Line 11: “sample sites” or “sampling sites”?
6. In Section 2.2, how did the authors quantify the concentration of WSOC in the snow samples? Did they randomly select different masses of snow samples for dissolution? Or snow need to be weighed? More information about experiment should be supplemented in the Experiment section
7. Page 6, Line 27：It is recommended to provide how inner filtration effect, Raman scattering and Rayleigh scattering are removed in EEM.
8. Page 6, Line 29: “As fluorescence spectra with wavelengths greater than 600 nm are primarily noise”, I would like to know why the authors measured excitation and emission wavelengths greater than 600 nm.
9. Page 7, Line 28: Please check Eq. 3.
10. Please provide the absorption measurement of WSOC in the method section.
11. Please provide the blank concentration of WSOC in the method section.
12. Page 10, Line 1-6: Suggest put it in the above paragraph.
13. Page 10, Line 23: The author should give the full name of “HULIS”.
14. Page 10, Line 25: “Wen et al. 2021”, format error.
15. Page 12, Line 15: Indeed, I don't know how the author obtained this conclusion, because the author only mentions SEIN and SNC here.
16. Page 14, Line 8: Can you really claim “monotonously”?
17. Page 14, Line 14-16: “FI values of ≤1.4 correspond to terrestrial sources and values of ≥1.9 denote a primarily microbial origin, values of 1.4–1.9 suggest a mixed origin.”. Suggest put it in Section 2. In addition, please provide references.
18. Page 15, Line 2: The result of TFV could not be seen in Figure 5a. Is it Figure 5b? as well as _WSOC (280).
19. Missing space in front of the unit in Figure 5 and elsewhere.
20. Page 16, Line 19: “P” should be “P”.
21. Page 17, Line 1-11: Suggest putting it in Section 1 (Introduction) and revising it appropriately.
22. Figure 7 should include the legend. In addition, in Line 11, Figure 7a refers to the absorption at wavelengths at 280-400 nm?
23. Page 23, Line 5, this sentence belongs to Section 2.
24. References: Please check the references and unified format. For example, “Characterization of Chromophoric Water-Soluble Organic Matter in Urban, Forest, and Marine Aerosols by HR-ToF AMS Analysis and Excitation–Emission Matrix Spectroscopy,” in Line 8.