Constructing a 22-year internal wave dataset for the northern South China Sea: spatiotemporal analysis using MODIS imagery and deep learning

<p>Internal waves (IWs) are an important ocean phenomenon facilitating energy transfer between multiscale ocean processes. Understanding such processes necessitates the collection and analysis of extensive observational data. IWs predominantly occur in marginal seas, with the South China Sea (...

Full description

Saved in:
Bibliographic Details
Main Authors: X. Zhang, X. Li
Format: Article
Language:English
Published: Copernicus Publications 2024-11-01
Series:Earth System Science Data
Online Access:https://essd.copernicus.org/articles/16/5131/2024/essd-16-5131-2024.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850199964536274944
author X. Zhang
X. Zhang
X. Li
X. Li
author_facet X. Zhang
X. Zhang
X. Li
X. Li
author_sort X. Zhang
collection DOAJ
description <p>Internal waves (IWs) are an important ocean phenomenon facilitating energy transfer between multiscale ocean processes. Understanding such processes necessitates the collection and analysis of extensive observational data. IWs predominantly occur in marginal seas, with the South China Sea (SCS) being one of the most active regions, characterized by frequent and large-amplitude IW activities. In this study, we present a comprehensive IW dataset for the northern SCS (<a href="https://doi.org/10.12157/IOCAS.20240409.001">https://doi.org/10.12157/IOCAS.20240409.001</a>, Zhang and Li, 2024), covering the area from 112.40 to 121.32° E and from 18.32 to 23.19° N, spanning the period from 2000 to 2022 with a 250 m spatial resolution. During the 22 years, a total of 15 830 MODIS images were downloaded for further processing. Out of these, 3085 high-resolution MODIS true-color images were identified to contain IW information and were included in the dataset with precise IW positions extracted using advanced deep learning techniques. IWs in the northern SCS are categorized into four regions based on extracted IW spatial distributions. This classification enables detailed analyses of IW characteristics, including their spatial and temporal distributions across the entire northern SCS and its specific sub-regions. Interestingly, our temporal analysis reveals characteristic “double-peak” patterns aligned with the lunar day, highlighting the strong connection between IWs and tidal cycles. Furthermore, our spatial analysis identifies two IW quiescent zones within the IW clusters influenced by underwater topography, highlighting regional variations in IW characteristics and suggesting underlying mechanisms which merit further investigation. There are also three gap regions between distinct IW clusters, which may indicate different IW sources. The constructed dataset holds significant potential for studying IW–environment interactions, developing monitoring and prediction models, validating numerical simulations, and serving as an educational resource to promote awareness and interest in IW research.</p>
format Article
id doaj-art-3edc7fbfb1ea4802a2cbac35a912f492
institution OA Journals
issn 1866-3508
1866-3516
language English
publishDate 2024-11-01
publisher Copernicus Publications
record_format Article
series Earth System Science Data
spelling doaj-art-3edc7fbfb1ea4802a2cbac35a912f4922025-08-20T02:12:29ZengCopernicus PublicationsEarth System Science Data1866-35081866-35162024-11-01165131514410.5194/essd-16-5131-2024Constructing a 22-year internal wave dataset for the northern South China Sea: spatiotemporal analysis using MODIS imagery and deep learningX. Zhang0X. Zhang1X. Li2X. Li3Key Laboratory of Ocean Observation and Forecasting, Qingdao, ChinaKey Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, ChinaKey Laboratory of Ocean Observation and Forecasting, Qingdao, ChinaKey Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China<p>Internal waves (IWs) are an important ocean phenomenon facilitating energy transfer between multiscale ocean processes. Understanding such processes necessitates the collection and analysis of extensive observational data. IWs predominantly occur in marginal seas, with the South China Sea (SCS) being one of the most active regions, characterized by frequent and large-amplitude IW activities. In this study, we present a comprehensive IW dataset for the northern SCS (<a href="https://doi.org/10.12157/IOCAS.20240409.001">https://doi.org/10.12157/IOCAS.20240409.001</a>, Zhang and Li, 2024), covering the area from 112.40 to 121.32° E and from 18.32 to 23.19° N, spanning the period from 2000 to 2022 with a 250 m spatial resolution. During the 22 years, a total of 15 830 MODIS images were downloaded for further processing. Out of these, 3085 high-resolution MODIS true-color images were identified to contain IW information and were included in the dataset with precise IW positions extracted using advanced deep learning techniques. IWs in the northern SCS are categorized into four regions based on extracted IW spatial distributions. This classification enables detailed analyses of IW characteristics, including their spatial and temporal distributions across the entire northern SCS and its specific sub-regions. Interestingly, our temporal analysis reveals characteristic “double-peak” patterns aligned with the lunar day, highlighting the strong connection between IWs and tidal cycles. Furthermore, our spatial analysis identifies two IW quiescent zones within the IW clusters influenced by underwater topography, highlighting regional variations in IW characteristics and suggesting underlying mechanisms which merit further investigation. There are also three gap regions between distinct IW clusters, which may indicate different IW sources. The constructed dataset holds significant potential for studying IW–environment interactions, developing monitoring and prediction models, validating numerical simulations, and serving as an educational resource to promote awareness and interest in IW research.</p>https://essd.copernicus.org/articles/16/5131/2024/essd-16-5131-2024.pdf
spellingShingle X. Zhang
X. Zhang
X. Li
X. Li
Constructing a 22-year internal wave dataset for the northern South China Sea: spatiotemporal analysis using MODIS imagery and deep learning
Earth System Science Data
title Constructing a 22-year internal wave dataset for the northern South China Sea: spatiotemporal analysis using MODIS imagery and deep learning
title_full Constructing a 22-year internal wave dataset for the northern South China Sea: spatiotemporal analysis using MODIS imagery and deep learning
title_fullStr Constructing a 22-year internal wave dataset for the northern South China Sea: spatiotemporal analysis using MODIS imagery and deep learning
title_full_unstemmed Constructing a 22-year internal wave dataset for the northern South China Sea: spatiotemporal analysis using MODIS imagery and deep learning
title_short Constructing a 22-year internal wave dataset for the northern South China Sea: spatiotemporal analysis using MODIS imagery and deep learning
title_sort constructing a 22 year internal wave dataset for the northern south china sea spatiotemporal analysis using modis imagery and deep learning
url https://essd.copernicus.org/articles/16/5131/2024/essd-16-5131-2024.pdf
work_keys_str_mv AT xzhang constructinga22yearinternalwavedatasetforthenorthernsouthchinaseaspatiotemporalanalysisusingmodisimageryanddeeplearning
AT xzhang constructinga22yearinternalwavedatasetforthenorthernsouthchinaseaspatiotemporalanalysisusingmodisimageryanddeeplearning
AT xli constructinga22yearinternalwavedatasetforthenorthernsouthchinaseaspatiotemporalanalysisusingmodisimageryanddeeplearning
AT xli constructinga22yearinternalwavedatasetforthenorthernsouthchinaseaspatiotemporalanalysisusingmodisimageryanddeeplearning