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arXiv · 2609.24591

Taking a Second Look: Correcting Sea Ice Forecasts with Sparse Observations

Tianshuo Zhang·Xianglei Xing·Aowen Yang·Jia Gao·Wenzhe Zhai·ShanShan Liu
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Abstract

Sea ice forecasts are issued several days ahead, allowing errors to accumulate while new, often sparse sea ice concentration (SIC) observations become available. We find that fixed-propagation errors concentrate near structured, high-gradient ice edges, whereas homogeneous interiors require limited propagation, suggesting that propagation distance should be state dependent. We therefore introduce ECHO (Evidence-guided Correction with Heterogeneous prOpagation), where ECHO-Scale adapts propagation distance while preserving correction geometry, and ECHO-Delta learns a bounded residual around fixed propagation. Across all 96 standard evaluation settings spanning diverse priors, observation times, sparsity levels, geometries, and noise conditions, both outperform fixed propagation. ECHO-Delta achieves the best average accuracy, while ECHO-Scale is more robust to geometry shifts. Code is available at https://github.com/yingtian22/TAKING-A-SECOND-LOOK.

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Tianshuo Zhang, Xianglei Xing, Aowen Yang, Jia Gao, Wenzhe Zhai, ShanShan Liu. 2026-09-21. Taking a Second Look: Correcting Sea Ice Forecasts with Sparse Observations. https://arxiv.org/abs/2609.24591

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