An Adaptive Spatiotemporal Clustering Framework for 3D Ocean Subsurface Temperature Reconstruction

TL;DR

This paper introduces an adaptive spatiotemporal clustering framework combined with deep learning models to improve the accuracy of ocean subsurface temperature reconstruction from surface observations.

Contribution

It presents a novel adaptive framework that captures vertical and temporal dependencies, enhancing deep learning models' performance in OST reconstruction.

Findings

Deep learning models with the framework outperform original models by 12.4% to 27.2% in RMSE.

The framework effectively captures spatiotemporal heterogeneity in ocean subsurface temperature.

The approach enables global OST reconstruction using only surface data.

Abstract

The reconstruction of ocean subsurface temperature (OST) using satellite remote sensing data holds significant scientific value for advancing the understanding of ocean dynamics and climate variability. However, the scarcity of subsurface observations, combined with the high degree of nonlinearity and spatiotemporal heterogeneity in subsurface processes, poses substantial challenges to the accuracy and generalization capability of traditional reconstruction methods. To address these limitations, this study proposes an adaptive framework that could capture both vertical structural dependencies and temporal variation patterns of OST via spatio-temporal clustering. By incorporating this framework with various deep learning models, e.g., dual-path convolutional neural networks (DP-CNN), Attention U-Net, and Vision Transformer (ViT), the OST field can be accurately reconstructed at a global scale only using surface observations, i.e., sea surface temperature (SST), sea surface salinity (SSS), sea surface height (SSH), and sea surface wind (SSW). Experimental results demonstrate that multiple deep learning methods using the proposed framework largely outperform their original counterparts, yielding improvements in RMSE ranging from 12.4\% to 27.2\%. This study provides a reliable solution for subsurface temperature reconstruction, offering important implications for meteorological modeling and climate change assessment.