Characterizing spatial patterns of satellite-derived chlorophyll-a in the Bohai and Yellow Seas of China using self-organizing maps (SOM) approach

Yueqi Wang; Dongyan Liu; Zhiqiang Gao; Yujue Wang; Meng Gao

doi:10.1016/j.marpolbul.2023.115176

Characterizing spatial patterns of satellite-derived chlorophyll-a in the Bohai and Yellow Seas of China using self-organizing maps (SOM) approach

Mar Pollut Bull. 2023 Aug:193:115176. doi: 10.1016/j.marpolbul.2023.115176. Epub 2023 Jun 29.

Authors

Yueqi Wang¹, Dongyan Liu², Zhiqiang Gao³, Yujue Wang⁴, Meng Gao⁵

Affiliations

¹ Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China; State Key Laboratory of Estuarine and Coastal Research, Institute of Eco-Chongming, East China Normal University, Shanghai, China. Electronic address: yueqiwang@yic.ac.cn.
² State Key Laboratory of Estuarine and Coastal Research, Institute of Eco-Chongming, East China Normal University, Shanghai, China. Electronic address: dyliu@sklec.ecnu.edu.cn.
³ Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China.
⁴ State Key Laboratory of Estuarine and Coastal Research, Institute of Eco-Chongming, East China Normal University, Shanghai, China.
⁵ School of Mathematics and Information Sciences, Yantai University, Yantai, Shandong, China.

PMID: 37392594
DOI: 10.1016/j.marpolbul.2023.115176

Abstract

Dynamic of chlorophyll-a (Chl-a) concentration is essential information to understand the status and trends of marine ecosystems. In this study, a Self-Organizing Map (SOM) was applied to delineate space-in-time patterns of Chl-a from satellite dataset during 2002-2022 over the Bohai and Yellow Seas of China (BYS). Six typical Chl-a spatial patterns were discerned through a 2 × 3 nodes SOM, while temporal evolutions of dominant spatial patterns were analyzed. The Chl-a spatial patterns were characterized by different concentrations and gradients, and obviously changed over time. The Chl-a spatial patterns and their temporal evolutions were mainly shaped by joint effects of nutrient level, light availability, water column stability, and other factors. Our findings provide first glimpse of space-in-time Chl-a dynamics in the BYS, and complement to the traditional time-in-space Chl-a pattern studies. The accurate identification and classification of the Chl-a spatial patterns are of great significance to marine regionalization and management.

Keywords: Bohai and yellow seas; Sea surface chlorophyll-a; Self-organizing maps; Space-in-time pattern.

MeSH terms

China
Chlorophyll / analysis
Chlorophyll A
Ecosystem*
Environmental Monitoring*
Oceans and Seas

Substances

Chlorophyll A
Chlorophyll