Seasonal Variations in Dissolved Organic Carbon in the Source Region of the Yellow River on the Tibetan Plateau

Round 1

Reviewer 1 Report

General comment: This paper investigated the seasonal variability of riverine DOC concentration, precipitation, discharge, temperature, and other variables of one catchment outlet over three years. As a result, DOC concentration in river water was related to precipitation and temperature whereas DOC concentration in rain water was diluted by precipitation. DOC export from the catchment was lower than expected in that region with glacier retreat. The topic is potentially interesting for the readers of Water. However, the manuscript needs some improvement before publication:

• Please show the data of temporal variability of DOC concentration of precipitation too (not only of DOC concentration of river water; Fig. 2), the paper is on seasonal variation.
• The average DOC concentration of the three annual means (2013-2015; Table 1) differs only by 1% between river and precipitation. This is within the measuring accuracy and not a significant difference! This suggests that all exported DOC is from rain water and almost nothing from the catchment. Therefore, I do not agree that the region has a strong DOC production potential (lines 339-340 in the conclusion).
• Please provide data of DOC load by precipitation (mg m-2 year-1) and the DOC export by the river (tons year-1) in the same units throughout the manuscript (abstract, Table 1, conclusion).

Minor comments:

1. Lines 14-15: The authors introduce the lack of long-term observation and continue with the present three-year study. However, three years are not long-term and do not fill the gap.
2. Line 17: Please provide ranges of seasonal variations (which is the title of the paper) instead the annual means of DOC concentration.
3. Line 34: More recent literature suggests higher numbers.
4. Line 64: Again: three years are not long-term.
5. Table 2: Did you correct the p values of the correlations for multiple tests (e.g., according to Benjamini Hochberg)?

Author Response

Thank the reviewers for the kind suggestions for revision. The revision instructions are in the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper “season variation of dissolved organic carbon in the source region of Yellow River on the Tibetan Plateau” is interesting research and very current.  

In the discussion, same part they should be explained better

However, are present some inaccuracy:

• Attention to reference (for exceptional lines 151)
• In the table 2 add decimal places
• Explain better: the relation to DOC concentration and fluxed in precipitation, it's not very clear

Author Response

Thanks very much for reviewer's kind comments. The modification instructions are in the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors provided a comprehensive revision of their manuscript. They considered almost all suggestions of the reviewers. As a result, the quality of the manuscript improved considerably. I have only one minor point: In my opinion, large parts of the conclusions contain too many results and numbers and are rather a summary of main findings.