!! Nov 2025: Updates and Dataset Information of a recent publication titled ‘Observed large-scale and deep-reaching compound ocean state changes over the past 60 years’ in Nature Climate Change (Tan et al., 2025) !! 🐋🐋

🔗 Tan, Z., K. v. Schuckmann, S. Speich, L. Bopp, J. Zhu, and L. Cheng. (2025): Observed large-scale and deep-reaching compound ocean state changes over the past 60 years. Nature Climate Change. https://www.nature.com/articles/s41558-025-02484-x

📚 Summary: This paper uses time-of-emergence (ToE) to highlight the increases in impacts of individual and compound changes globally from the surface to the deeper ocean, identifying areas most affected.

📕 PDF: This paper could be downloaded here.

🎥 Dashboard: A dashboard is available here to enable the climate scientists and climate policy-makers to check the dynamic evolution (since 1985) and current state of the simultaneous change in the global ocean.

📊 Dataset: The IAP Compound climatic impact-drivers (CIDs) monitoring dataset (version 0.1) can be accessed here. This dataset provides the time of emergence (ToE) for individual CIDs (temperature, salinity, dissolved oxygen, and surface pH) and their compound changes estimation from 1980 to 2023 at 1-degree box from 0-1000m in the global ocean. A backup link to download this dataset is here.

▶️ Video: an evolution of the changing compound CIDs (ToE and its exposure) from 1980 to 2023 can be reached here

🐍 Codes: The codes to reproduce the key figures (Figure 2 and Figure 3 of Tan et al., 2025) can be accessed via the IAP ocean’s team website.

🐍 Codes: Demo codes of the calculation of time-of-emergence (ToE) using the temperature gridded product can be reached in the GitHub repository.

♻️ The GitHub repository also provides more information on the datasets, codes, and demos of the IAP Compound CIDs monitoring dataset. All future updates will be upload to my GitHub repository and IAP ocean’s team website.

📄 News/Press/Reports:

​ 📎 EurekAlert

About Me 🐋

I am a Ph.D. specializing in Physical Oceanography, Operational Oceanography, and ocean climate change impact, with a particular focus on ocean observations and data quality improvements, water mass and ocean circulation, ocean compound climate change, ocean warming monitoring, and compound risk assessment. I hold my Ph.D from the Institute of Atmospheric Physics, Chinese Academy of Sciences (Supervisors: Prof. CHENG Lijing and Prof. ZHU Jiang) in July 2024.

Currently, I am a post-doc investigator at Department of Geosciences (Laboratoire de Météorologie Dynamique), École Normale Supérieure (ENS), Université Paris Sciences et Lettres (PSL) since Feb 2025 (Advisors: Prof. Sabrina Speich and Prof. Elaine McDonagh), working for Ice sheet impacts on global ocean circulation (WP5) of the OCEAN:ICE project funded by Horizon Europe.

Particularly, I mainly focused on the study of ‘climate impact-drivers’ (e.g., temperature, salinity, dissolved oxygen etc.) which connect physical ocean changes to broader climate impacts. I used ocean climate data to identify the climate ‘hot spot’ regions mostly affected by the compound climate changes and developed frameworks to assess these impacts. I also investigated the salinity and freshwater budget of the South Atlantic Ocean, focus on the regional salinity redistribution processes and its link to AOMC under climate change.

Besides, I am the member of International Quality Controlled Ocean Database (IQuOD). I specialize in ocean data processing and analysis, significantly improving the quality of ocean observational data. These efforts included: 1) development of advanced data quality systems by creating open-source tools in the ocean science community for data validation and quality control (e.g., XBT bias correction schemes, data QC system, data duplicate checking etc.). 2) Innovative data analysis techniques such as employed statistical methods to analyze climate data trends and variations (detection & attribution etc.).

Research Interests

You can find my CV here

中文简历可以在这里获取

!! News in Tan et al., 2025, Scientific Data !! 🐋🐋

The global in-situ salinity profiles dataset since 1940s was published in Scientific Data and is now freely available

📎 Dataset: This salinity dataset (namely CODC-S) can be freely downloaded via http://www.ocean.iap.ac.cn/ftp/cheng/CODCv2.1_Insitu_T_S_database/ or https://doi.org/10.12157/IOCAS.20241217.001

🗂️ The second version (v2.1) of the CODC Global Ocean Temperature and Salinity Profile Science Database (CAS- Oceanographic Data Center, Global Ocean Science Database: CODC-v2) was led by the Institute of Atmospheric Physics, Chinese Academy of Sciences, a co-founding institution of the Oceanographic Science Data Center, Chinese Academy of Sciences, in collaboration with the Institute of Oceanology, Chinese Academy of Sciences, the Computer Network Information Center, Chinese Academy of Sciences, and other organizations. The database provides ocean temperature and salinity profile data that have been quality-controlled and bias-corrected. The database covers observational data from 1940 onwards, sourced from 14 types of observation instruments, including XBT, CTD, Argo, gliders, and buoys. It contains 18,472,149 temperature profiles and 11,273,326 salinity profiles (statistics from January 1940 to November 2024). These salinity profiles are quality-controlled (QC-ed) using a new automated salinity quality control system named CODC-QC-S (the CODC Quality Control system – Salinity component), consisting of 11 distinct quality checks.

📈 For efficiently reuse in the community, we also put the CODC temperature (CODC-T) profiles (Zhang et al., 2024) together in the same folder.

🧾I am responsible to maintain and update this dataset. For any question, please do not hesitate to tell me.

📚 Citation: Tan Z, Zhu Y, Cheng L*, Gouretski V, Pan Y, Yuan H, Wang Z, Li G, Song X, Zhang B, Bao S, Li Y, Zhu J. 2025. CODC-S: A quality-controlled global ocean salinity profiles dataset. Scientific Data, 12: 917. https://doi.org/10.1038/s41597-025-05172-9

Publication lists

Total citations: 570+, H-index: 10, i-10 index: 10 (Google Scholar, 01/2026)

2026:

[1] Liu Xu, Licheng Feng, Lijing Cheng, Zhetao Tan, Cuijuan Sui, Chunyang Song (2026): Spatiotemporal Changes of Ocean Heat Content in the Seas around China. Advances in Atmospheric Sciences. 1-19

[2] Yuying Pan, Lijing Cheng, John Abraham, Kevin Trenberth…., Zhetao Tan,…. Miao Zhang, Lin Chen (2026): The Ocean Heat Content Sets New Records in 2025 Signals Accelerated Climate Warming. Advances in Atmospheric Sciences. 1-23

2025:

[1] Tan, Z., K. v. Schuckmann, S. Speich, L. Bopp, J. Zhu, and L. Cheng. (2025): Observed large-scale and deep-reaching compound ocean state changes over the past 60 years. Nature Climate Change. https://doi.org/10.1038/s41558-025-02484-x

[2] Tan Z, Zhu Y, Cheng L, Gouretski V, Pan Y, Yuan H, Wang Z, Li G, Song X, Zhang B, Bao S, Li Y, Zhu J. 2025. CODC-S: A quality-controlled global ocean salinity profiles dataset. Scientific Data, 12: 917. https://doi.org/10.1038/s41597-025-05172-9

[3] Cheng L. J. Abraham, K. E. Trenberth, J. Reagan, H.-M. Zhang, A. Storto, K. Von Schuckmann, Y. Pan, Y. Zhu, M. E. Mann, J. Zhu, F. Wang, F. Yu, R. Locarnini, J. Fasullo, B. Huang, G. Graham, X. Yin, V. Gouretski, F. Zheng, Y. Li, B. Zhang, L. Wan, X. Chen, D. Wang, L. Feng, X. Song, Y. Liu, F. Reseghetti, S. Simoncelli, G. Chen, R. Zhang, A. Mishonov, Z. Tan, W. Wei, H. Yuan, G. Li, Q. Ren, L. Cao, Y. Lu, J. Du, K. Lyu, A. Sulaiman, M. Mayer, H. Wang, Z. Ma, S. Bao, H. Yan, Z. Liu, C. Yang, X. Liu, Z. Hausfather, T. Szekely, F. Gues: 2025: Record High Temperatures in the Ocean in 2024. Advances in Atmospheric Sciences.

2024:

[1] X. Song†, Z. Tan†, R. Locarnini, S. Simoncelli, R. Cowley, S.i Kizu, T. Boyer, F. Reseghetti, G. Castelao, V. Gouretski, L. Cheng, 2024: An open-source algorithm for identification of duplicates in ocean database. Frontier in Marine Science. 11. [co-first author, supervised a MS student]

[2] Cheng, L., Pan, Y., Tan, Z., Zheng, H., Zhu, Y., Wei, W., Du, J., Yuan, H., Li, G., Ye, H., Gouretski, V., Li, Y., Trenberth, K., Abraham, J., Jin, Y., Reseghetti, F., Lin, X., Zhang, B., Chen, G., Mann, M., and Zhu, J., 2024: IAPv4 ocean temperature and ocean heat content gridded dataset, Earth Syst. Sci. Data.

[3] Zhang B., L. Cheng, Z. Tan, V. Gouretski, F. Li, Y. Pan, H. Yuan, H. Ren, F. Reseghetti, J. Zhu, and F. Wang, 2024: CODC-v1: a quality-controlled and bias-corrected ocean temperature profile dataset from 1940-2023. Scientific Data, 11(1), 666

[4] Yuan H., L. Cheng, Y. Pan, Z. Tan, Q. Liu, Z. Jin, 2024: A multi-level parallel approach to increase the computation efficiency of a global ocean temperature dataset reconstruction. *Journal of Parallel and Distributed Computing, 104938.

[5] Viktor Gourteski, Lijing Cheng, Juan Du, Xiaogang Xing, Fei Chai, Zhetao Tan. 2024: A consistent ocean oxygen profile dataset with new quality control and bias assessment. Earth Syst. Sci. Data. 2024, 1-27,

[6] Cheng L… Z. Tan, … Y. Lu, 2024: New record ocean temperatures and related climate indicators in 2023, Advances in Atmospheric Sciences

[7] Yuan H., T. Li, Z. Jin., L. Cheng, Z. Tan, B. Zhang, Y. Wang., 2024: CODC-pyParaQC: A design and implementation of parallel quality control for ocean observation big data. 2024 IEEE International Symposium on Parallel and Distributed Processing with Applications, 2024, pp. 1863-1870.

[8] Simoncelli, S., Cowley, R., Tan, Z., Killick, R., Castelão, G., Cheng, L., Good, S., Boyer, T., Mills, B., Bhaskar, U., & Locarnini, R. (2024). The International Quality-controlled Ocean Database (IQuOD). Miscellanea INGV, 80, 139–140.

2023:

[1] Tan Z., Cheng L., Gouretski V., Zhang B., Wang Y., Li F., Liu Z., Zhu J., 2023: A new automatic quality control system for ocean in-situ temperature observations and impact on ocean warming estimate. Deep-Sea Research Part I, 194, 103961

2022:

[1] Tan, Z., B. Zhang, X. Wu, M. Dong, L. Cheng, 2022: Quality control for ocean observations: From present to future. Science China-Earth Sciences, 65(2):215-233

[2] Liu, Y, L. Cheng, Y. Pan, Z. Tan, J. Abraham, B. Zhang, J. Zhu, and J. Song, 2022: How well do CMIP6 and CMIP5 models simulate the climatological seasonal variations of ocean salinity? Advances in Atmospheric Sciences

[3] Cheng, L., J. Abraham, K. E. Trenberth, J. Fasullo, T. Boyer, M. E. Mann, J. Zhu, F. Wang, R. Locarnini, Y. Li, B. Zhang, Z. Tan, F. Yu, L. Wan, X. Chen, X. Song, Y. Liu, F. Reseghetti, S. Simoncelli, V. Gouretski, G. Chen, A. Mishonov, J. Reagan, 2022: Another record: Ocean warming continues through 2021 Despite La Niña Conditions. Advances in Atmospheric Sciences.

2021:

[1] Tan Z., Reseghetti F, Abraham J, Cowley R, Chen K, Zhu J, Zhang B, Cheng L, 2021: Examining the Influence of Recording System on the Pure Temperature Error in XBT Data. Journal of Atmospheric and Oceanic Technology, 38, 759-776.

[2] Zhang B., F. Li, G. Zheng, Y. Wang, Z. Tan, X. Li, 2021: Developing big ocean system in support of Sustainable Development Goals: challenges and countermeasures. Big Earth Data, 5(4), 557-575.

Contact Information

✉️ zhetao.tan@lmd.ipsl.fr or tanzhetao19@mails.ucas.ac.cn

Tel: (+33) 699130934 ; (+86) 13413812907