Projections of Mean and Extreme Precipitation Using the CMIP6 Model: A Study of the Yangtze River Basin in China
Round 1
Reviewer 1 Report
This paper has attempted to rank selected models from the CMIP6 suit in terms of their suitability to simulate extreme precipitation in the Yangtze River Delta, China. The paper mentions about 11 extreme precipitation indices but then goes on to say that “We evaluate the model's ability to simulate the spatial distribution of precipitation and average annual mean precipitation for the historical period (1985-2014) in the model evaluation stage”. There also seems to be is a mismatch between the title and objective of the paper stated in the beginning of the Abstract. This should be addressed.
I have the following suggestions for the authors:
1. For improved clarity and ease in understanding, I suggest the authors to include a flow chart informing the procedure/steps followed in the analysis.
2. This study has focused only on the Yangtze River Delta. Normally, hydro-met studies cover the whole basin. It will help to inform why the whole basin was not selected and only a part was studied ?
3. Authors: please describe the study area using a map. The map should show the key features of interest which may impact the climate and precipitation patterns in the basin – dams, diversions, major rivers, forests, etc. If some features of interest such as landuse-land cover are likely to undergo big changes in future, this should also be described as these changes may have impact on future climate.
4. Authors mentioned that the CN05.1 dataset, obtained by Wu et al. (2013) based on processed observations from 2,416 ground-based meteorological stations in China was used in the study. Please describe what other datasets are available for China and why CN05.1 was used?
Minor edits
5. Line 126: please explain the term “rlilplfl”.
6. Line 176: the maximum possible correlation coefficient will be +-1. Right ?
7. Line 191: the meaning is not clear. Please explain in more details how variables of eq. (6) are calculated.
8. In general, the paper is well-written but the language needs improvements at some places.
The language needs improvements at some places. A thorough reading of the paper would help.
Author Response
请参阅附件
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript assessed precipitation variability, as well as trends, in both the current and projected climate for the Yangtze River Delta. While this kind of study is of particular significance for regional planners and should be explored, I have some significant concerns about the approach. I recommend that the manuscript be returned for Major Revisions prior to publication.
Major Comment: The authors state in line 127 that they use only a single member (r1i1p1f1) from each model. These single members are then used to calculate a variety of statistics, including trends, over a relatively limited geographic region. However, previous work (e.g. Deser et al 2014) has shown that internal variability can play a dominant role in the calculation of trends for limited regions (see their figures 2 and 3). It is thus difficult to assess the significance of the presented results, because they rely on a single ensemble member and could be dominated by internal variability. I feel strongly that the analysis presented must be repeated with multiple ensemble members in order to determine the robustness of the results.
Minor comments:
Line 42-43: Reference needed
Line 100: Formatting
Line 144-147: Please expand upon this discussion, including the value at which the cut off is applied.
Line 153: Reference for ROUANT
Equation 3: Is this assuming that there is no change in the transfer function under the future climate?
Lines 178-179: A score of zero indicates a better model, even though this occurs when the correlation is negative?
Line 339: What method is used to assess significance of the trend?
Author Response
Please see the attachment
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
I commend the authors for thoroughly addressing the concerns raised in my original review, and believe the manuscript is now suitable for publication.
