资源环境科技发展态势分析平台

The spatiotemporal variabilities and drivers of ocean acidification (OA) metrics, [H⁺], pH, and aragonite saturation state (Ω_arag) across environmental gradients remain poorly constrained. We use a novel high-precision measurement of underway pH to investigate the hemispheric-scale distributions of OA metrics from East Asia to the Arctic Ocean. While temperature and its induced air-sea gas exchange fundamentally control the OA metrics distributions, we show that biological activity exerts the most prominent but different modifications on pH and Ω_arag patterns. Strong photosynthesis counteracts the temperature-driven pH pattern but reinforces that of Ω_arag. Ice melt-induced dilution in the Arctic Ocean additionally strengthens the Ω_arag-temperature relationship but insignificantly affects [H⁺] and pH. This study provides the first coherent assessment of comprehensive processes on OA metrics across large spatial regions, and highlights the potential of sea-ice melt in changing Ω_arag distribution, which should be included by Earth system models projecting future climate change.