We thank the members of the Japan Agency for Marine–Earth Science and Technology (JAMSTEC) Argo group. Mr. Ohira in the JAMSTEC Argo group calculated the difference between Argo data and World Ocean Atlas 2001 data. The Argo float data used in this study were collected and made freely available by the International Argo Project and the national programs that contribute to it (information online at http://www.argo.ucsd.edu and http://argo.jcommops.org).
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