Seasonal M2 Internal Tides in the Arabian Sea

Jingyi Ma,Daquan Guo,Ibrahim Hoteit,Peng Zhan

doi:10.3390/rs13142823

Abstract

Internal tides play a crucial role in ocean mixing. To explore the seasonal features of mode-1 M2 internal tides in the Arabian Sea, we analyzed their propagation and energy distribution using along-track sea-level anomaly data collected by satellite altimeters. We identified four primary source regions of internal tides: Abd al Kuri Island, the Carlsberg Ridge, the northeastern Arabian Sea, and the Maldive Islands. The baroclinic signals that originate from Abd al Kuri Island propagate meridionally, whereas those originating from the west coast of India propagate southwestward. The strength and energy flux of the internal tides in the Arabian Sea exhibit significant seasonal and spatial variability. The internal tides generated during winter are more energetic and can propagate further than those generated in summer. Doppler shifting and horizontal variations in stratification can explain the differences in the internal tides’ seasonal distributions.

Highlights

Internal tides, known as baroclinic tides with tidal frequencies, may lead to prominent preconditioning of ocean mixing [1]
We first describe the general characteristics of the internal tides in the Arabian Sea and examine their seasonal variabilities
We examined the general properties of internal tides and their seasonality in the Arabian Sea, including the Red Sea and the Arabian Gulf

Summary

Introduction

Known as baroclinic tides with tidal frequencies, may lead to prominent preconditioning of ocean mixing [1]. Internal tides play an important role in both physical and biochemical processes in the ocean. Internal tides could be one of the driving forces of the Meridional Overturning Circulation (MOC), which is a major component of the climate system [7,8]. Internal tides can promote ocean mixing, connecting the deep ocean with the entire Earth system [3]. They can transport the frequent pulses of nutrients, which cause algal blooms in shallow depths, the areas that are generally more nutrient-limited than the deep ocean [9]

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