A Comparative Study of the Argo‐Era Ocean Heat Content Among Four Different Types of Data Sets

Abstract

AbstractWe conducted a comparative study of ocean heat content (OHC) in the top 2,000 m during the Argo‐era using 12 latest and representative global ocean data sets. The differences in the global and basins‐wide OHC trends were minor among the observation‐based data sets, and remarkable among the ocean reanalyzes (RAs). Some RAs might exhibit much higher or lower basins‐wide warming rates than the observation‐based data sets. In the top 700 m, RAs suggested similar large‐scale warming and cooling patterns, in agreement with the observation‐based data sets. Below 700 m, the major warming and cooling features were significantly different between RAs and the observation‐based data sets. All data sets suffered from relatively larger uncertainties in the highly dynamic regions. Special caution is suggested when estimating the OHC using only a single data set, especially a RA. Differences of RAs' OHC from observation‐based data sets were significantly reduced when considering their ensemble mean, to be further confirmed with a larger sample of data sets.