Dear Qinghua and Co-authors,

Thank you for providing a detailed response addressing the reviewers points and including additional data sets. Please provide a revised manuscript. Your response and suggested changes are convincing, so I will only send it back for further review if parts in the manuscript are unclear to me. However, I would like to raise one point to consider: Figure 1 in your response to Rev#1 shows systematic differences between NSIDC and OSI ice drift. Not sure it is best strategy to average over both products. Might be more appropriate to use both data sets individually and to derive estimate of uncertainty from difference. In any case, please discuss this properly in revised manuscript.
Kind regards,
David

Dear Qinghua and Co-authors,

Thank you for your revised manuscript incorporating the comments and suggestions made by the reviewers. The manuscripts will be accepted for publication after you can clarify one remaining issue:
You provide several numbers with standard deviations in Abstract, Results and Conclusion. However, it is not clear whether the standard deviation refers to inter-annual variability (2011-2016 period) or whether it is a measure of uncertainty (difference between the merged data products). Please clarify and add paragraph how these numbers are calculated.
Kind regards,
David

Dear Qinghua and Co-authors,

I would recommend to clarify/repeat that standard deviation refers to ensemble members in Abstract and Results, too. Otherwise reader would assume you present inter-annual variability.

Kind regards,
David