太平洋中的主要起伏模态

对海洋中起伏运动(heaving)信号的时空分布研究能够帮助我们更好地了解气候系统中的年际和年代际变率。文章通过再分析资料和模式对太平洋区域的heaving主要模态进行了研究。研究结果表明: 太平洋区域主要存在两种heaving模态: 第一模态主要表现为赤道东西两侧的温跃层异常信号反位相; 第二模态表现为赤道区域和副热带区域的温跃层异常信号呈现反位相变化的规律。本文对这两个主要heaving模态所涉及的物理过程进行详细讨论, 结果表明: 东西反位相模态主要是受赤道波动调节的结果; 而经向结构模态则主要是由赤道地区的波动和副热带区域的风应力旋度异常作用共同导致。此外, 我们还讨论了heaving模态可以通过海洋波动以及Ekman输送等过程对海盆尺度的热输送(振幅约为5×10¹⁴W)以及海洋热含量(振幅约为1.5×10²⁰J)的再分配起到了关键的调制作用, 进一步表明heaving模态对全球气候变化有着重要的作用。

The main heaving modes in the Pacific Ocean

The spatial-temporal variability of heaving mode in the ocean is critical to understanding climate variability on interannual and decadal time scales. Using reanalysis data and a reduced gravity model, we investigated the leading heaving modes in the Pacific Ocean. The heaving signals are dominated by two modes: the first mode in which thermocline depth anomalies in the eastern and western equatorial Pacific have opposite signs, and the second mode in which thermocline depth anomalies in the equatorial and subtropical Pacific Ocean have opposite signs. The time evolution of these two heaving modes and the physics leading to these two modes were explored. Results indicate that the first mode is directly linked to equatorial zonal wind anomalies, and the second mode is induced by the wind stress curl anomaly in the subtropics. Furthermore, these two leading heaving modes have profound impacts on basin-scale heat transport (with an amplitude of 5?10¹⁴W) and ocean heat content redistribution (with an amplitude of 1.5×10²⁰J) through ocean waves and Ekman transport, highlighting the importance of heaving modes in modifying the variabilities of the climate system and climate change.