Editorial Comments:
1) Length of Introduction: Agree with the reviewer #1 that it is too long. I suggest it to be reduced by 30%
2) Page 19, lines 14-15: A brief description of the river routing scheme in the model should be discussed
3) Page 21, the spin up issue: I suggest the authors to add time series of DIC and alkalinity to demonstrate that the model has indeed reached steady state.
4) In response to the general comment of reviewer #2, I suggest the authors to discuss, if not quantify, the uncertainty issues in the manuscript
5) In response to the following specific comments by reviewer #2, I ask the authors to address them in the revised manuscript:
6) Page 15, lines 14-17
7) Page 21, lines 2-8
8) Page 21, lines 13-16
9) Page 26, lines 20-22
10) Page 27, lines 2-3
11) Page 25, lines 18-20; Page 29, lines 9-12: Suggest to show the evolution of carbon in CaCO3 component of the sediments
12) Page 28, lines 1-4
13) Page 28, lines 9-15
14) Page 35, lines 1-4