Climate Variability Patterns and Their Ecological Effects on Ecosystems in the Northwestern North Pacific

Shuyang Ma,Yang Liu,Haiqing Yu,Peng Sun,Jiahua Cheng,Yongjun Tian,Caihong Fu,Yoshiro Watanabe,Jianchao Li

doi:10.3389/fmars.2020.546882

Abstract

Climate-induced ecosystem variability is increasingly concerning in recent years. Integrated researches in the northeastern North Pacific have proved the ecological importance of the Pacific Decadal Oscillation (PDO), North Pacific Gyre Oscillation (NPGO) and El Nino-Southern Oscillation (ENSO) to ecosystem variability. While in the northwestern North Pacific, researches have been independent of each other over different regional ecosystems, and identified relatively weak linkages between these climatic indices (e.g. PDO, NPGO, and ENSO) and variations in the regional ecosystems. Such disassociated researches with unidentified important climate variability patterns may have hampered a holistic understanding of climate-induced ecosystem variability in the northwestern North Pacific. Furthermore, non-stationarity in climate-biology relationships has been proven to be important for ecosystems in the northeastern North Pacific but has not yet been studied in the northwestern North Pacific. Therefore, this research compiles biological, environmental and climatic data in ecosystems in the northwestern North Pacific and employs a suite of analytical techniques, aiming to provide a holistic understanding of the climate-induced ecosystem variability. It shows that ecosystems in the northwestern North Pacific had a leading regime shift in the late 1980s in response to climate variability. The Siberian High, Arctic Oscillation and East Asian Monsoon exhibit greater ecological importance to ecosystem variability than the PDO, NPGO and ENSO. Their variations contribute greatly to sea surface temperature changes and thus variations in ecosystems. Furthermore, modified models considering non-stationary relationships achieve better performances than stationary models, suggesting the existence of non-stationarity in climate-biology relationships in the northwestern North Pacific. This non-stationarity resulted from the decline in variance of the sea level pressure in Siberian High rather than the Aleutian Low as suggested by previous studies in the northeastern North Pacific. Our research provides an improved understanding of the climate-induced ecosystem variability in the northwestern North Pacific, offering implications for furthering research on the entire North Pacific.

Highlights

Climate-induced ecosystem variability has been one of the most noteworthy issues at a global scale in the 21st century (Doney et al, 2012)
The first four PCs explain 63.19% of the total variance in ecosystem variability (Figure 3) with loadings on PCs shown in Supplementary Figure S3
PCs are characterized by significant multidecadal to decadal variability patterns with the most concentrated step-like changes in the late 1980s, which indicates that an ecosystem regime shift in the northwestern North Pacific may have happened in the late 1980s

Summary

Introduction

Climate-induced ecosystem variability has been one of the most noteworthy issues at a global scale in the 21st century (Doney et al, 2012). Studies in Chinese (Ma et al, 2019), Korean (Zhang et al, 2000, 2007), and Japanese waters (Tian et al, 2006, 2008; Yatsu et al, 2013) have all demonstrated strong linkages between regional ecosystems and climatic/environmental conditions. These regional studies have not yet been integrated to show general patterns in climate–ecosystem relationships, which prevents from a holistic understanding of climate-induced ecosystem variability in the northwestern North Pacific. An integrated study targeting at the northwestern North Pacific is in urgent need, which can promote understanding on the basin-scale climateinduced ecosystem variability in the North Pacific

Objectives

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Results

Conclusion