Warm pool ocean heat content regulates ocean–continent moisture transport
Warm pool ocean heat content regulates ocean–continent moisture transport
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DOI：
10.1038/s41586-022-05302-y
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发表时间：
2022-10
期刊：
影响因子：
64.8
通讯作者：
Z. Jian;Yue Wang;H. Dang;M. Mohtadi;Y. Rosenthal;D. Lea;Zhongfang Liu;Haiyan Jin;Liming Ye
中科院分区：
文献类型：
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作者：
Z. Jian;Yue Wang;H. Dang;M. Mohtadi;Y. Rosenthal;D. Lea;Zhongfang Liu;Haiyan Jin;Liming Ye
印度-太平洋暖池（IPWP）通过向大气释放大量的水蒸气和潜热，调节海洋上层热含量（OHC），在全球气候中发挥主导作用，这与现代气候变化有关。然而，IPWP热含量的长期变化及其对季风水文气候的影响尚未得到充分探讨。结合地球化学指标和瞬态气候模拟，我们发现过去36万年IPWP上层（0 ~ 200 m）热含量的变化表现为主要的进动和较弱的倾角旋回，并遵循经向日照梯度的变化，只有30% ~ 40%的冰量增加与冰量变化有关。在岁差带，较高的上层热含量与IPWP地表水的氧同位素富集和伴随的东亚降水耗竭有关。利用同位素驱动的海气耦合模式，我们认为在进动时间尺度上，IPWP上层热含量的变化比地表温度的变化更能通过水汽和潜热的辐合放大海洋-大陆水循环。从能量的角度来看，高层热含量与季风变化的耦合，都是由轨道时间尺度上的日照变化协调的，对调节全球水文气候至关重要。
The Indo-Pacific Warm Pool (IPWP) exerts a dominant role in global climate by releasing huge amounts of water vapour and latent heat to the atmosphere and modulating upper ocean heat content (OHC), which has been implicated in modern climate change. The long-term variations of IPWP OHC and their effect on monsoonal hydroclimate are, however, not fully explored. Here, by combining geochemical proxies and transient climate simulations, we show that changes of IPWP upper (0–200 m) OHC over the past 360,000 years exhibit dominant precession and weaker obliquity cycles and follow changes in meridional insolation gradients, and that only 30%–40% of the deglacial increases are related to changes in ice volume. On the precessional band, higher upper OHC correlates with oxygen isotope enrichments in IPWP surface water and concomitant depletion in East Asian precipitation as recorded in Chinese speleothems. Using an isotope-enabled air–sea coupled model, we suggest that on precessional timescales, variations in IPWP upper OHC, more than surface temperature, act to amplify the ocean–continent hydrological cycle via the convergence of moisture and latent heat. From an energetic viewpoint, the coupling of upper OHC and monsoon variations, both coordinated by insolation changes on orbital timescales, is critical for regulating the global hydroclimate.