Tropical oceans are the main global water vapor and latent heat sources, but their responses to radiative forcing remain unclear. Here, we investigate oceanic moisture dynamics of the western tropical Pacific (WTP) over the past 210,000 years through an approach of planktonic foraminiferal triple oxygen isotope (Δ′ 17 O). The Δ′ 17 O record is dominated by the precession cycles (~23,000 years), with lower values reflecting higher humidity in concert with higher Northern Hemisphere summer insolation. Our empirical and modeling results, combined with other geological archives, suggest that the enhanced moisture convergence over the WTP largely intensifies changes in the meridional and zonal hydrological cycles, affecting rainfall patterns in East Asia and northern South America. We propose that the insolation-driven WTP moisture dynamics play a pivotal role in regulating tropical hydroclimate.

中文翻译：

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三重氧同位素揭示了日照强迫的热带水汽循环


热带海洋是全球主要的水蒸气和潜热源，但它们对辐射强迫的响应仍不清楚。在这里，我们通过浮游有孔虫三氧同位素 （Δ′ 17 O） 的方法研究了过去 210,000 年西热带太平洋 （WTP） 的海洋水分动力学。Δ′ 17 O 记录以岁差周期（~23,000 年）为主，较低的值反映较高的湿度与较高的北半球夏季日照相一致。我们的实证和建模结果，结合其他地质档案，表明 WTP 上增强的水分收敛在很大程度上加剧了经向和纬向水文循环的变化，影响了东亚和南美洲北部的降雨模式。我们提出日照驱动的 WTP 水分动力学在调节热带水文气候中起着关键作用。