⚠️ Please note that the dataset is still in the process of being uploaded. ⚠️ Due to Zenodo's file size limitations, the dataset is divided into three parts for upload : 2000-2007,2008-2015,2016-2024. This dataset provides a global, daily, gap-filled ocean colour product for surface chlorophyll‑a (Chl‑a), covering the period 2000 to 2024 at a spatial resolution of 9 km. The product was generated using a GPU-accelerated Discrete Cosine Transform and Penalized Least Squares (DCT–PLS) spatiotemporal reconstruction framework. The input data are derived from the Ocean Colour Climate Change Initiative (OC-CCI) Version 6.0, a multi-sensor merged product developed by the European Space Agency. Each NetCDF file contains daily reconstructed chlorophyll‑a fields for one calendar year. Creator: Yuan Zhang Email: zhangyuan_cumt@cumt.edu.cn Institution: School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, China Orcid: https://orcid.org/0009-0006-0146-0385 ResearchGate: https://www.researchgate.net/profile/Yuan-Zhang-249