Subsurface oceanic structure associated with atmospheric convectively coupled equatorial Kelvin waves in the eastern Indian Ocean
Subsurface oceanic structure associated with atmospheric convectively coupled equatorial Kelvin waves in the eastern Indian Ocean
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DOI：
10.1029/2021jc017171
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发表时间：
2021-03
期刊：
影响因子：
--
通讯作者：
M. Azaneu;A. Matthews;D. Baranowski
中科院分区：
文献类型：
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作者：
M. Azaneu;A. Matthews;D. Baranowski
大气对流耦合赤道Kelvin波（CCKWs）是一种受海洋-大气相互作用强烈影响的主要热带天气特征。然而，预测CCKW的发展和传播仍然是模型的一个挑战。这些相互作用所涉及的物理过程进行评估，通过调查的CCKW通过印度洋东部和MC使用NEMO海洋模式分析与数据同化的海洋响应。三维生命周期构造的“孤立”CCKW事件。作为一个CCKW传播在东印度洋，直接的海洋热力学响应包括海洋表面和次表层的冷却，加深的混合层深度，并在混合层热含量的增加。此外，动态下降流信号观察到两天后，在CCKW西风爆发，它向东传播沿着赤道，然后遵循苏门答腊和爪哇海岸，与下降流海洋开尔文波的平均相速度为2.3米秒-1的峰值。纬向速度异常的经向和垂向结构与这一框架是一致的。这种动力学特征在不同的CCKW种群中是一致的，表明CCKW作为东印度洋海洋开尔文波的重要来源。地下动力响应CCKW是可识别的11天后，强迫。这些海洋反馈的时间尺度长于CCKW的生命周期，有助于阐明如何当地驱动的过程可以纠正到更长的时间尺度的过程中耦合的海洋-大气系统。
Atmospheric convectively coupled equatorial Kelvin waves (CCKWs) are a major tropical weather feature strongly influenced by ocean--atmosphere interactions. However, prediction of the development and propagation of CCKWs remains a challenge for models. The physical processes involved in these interactions are assessed by investigating the oceanic response to the passage of CCKWs across the eastern Indian Ocean and MC using the NEMO ocean model analysis with data assimilation. Three-dimensional life cycles are constructed for "solitary" CCKW events. As a CCKW propagates over the eastern Indian Ocean, the immediate thermodynamic ocean response includes cooling of the ocean surface and subsurface, deepening of the mixed layer depth, and an increase in the mixed layer heat content. Additionally, a dynamical downwelling signal is observed two days after the peak in the CCKW westerly wind burst, which propagates eastward along the Equator and then follows the Sumatra and Java coasts, consistent with a downwelling oceanic Kelvin wave with an average phase speed of 2.3 m s-1. Meridional and vertical structures of zonal velocity anomalies are consistent with this framework. This dynamical feature is consistent across distinct CCKW populations, indicating the importance of CCKWs as a source of oceanic Kelvin waves in the eastern Indian Ocean. The subsurface dynamical response to the CCKWs is identifiable up to 11 days after the forcing. These ocean feedbacks on time scales longer than the CCKW life cycle help elucidate how locally driven processes can rectify onto longer time-scale processes in the coupled ocean--atmosphere system.