Remote impacts of 2009 and 2015 El Ni\xf1o on oceanic and biological processes in a marginal sea of the Northwestern Pacific

Yoonho Jung,Sang-Wook Yeh,Kuk Jin Kim,Jae-Hun Park,Naoki Hirose,Ho Kyung Ha

doi:10.1038/s41598-021-04310-8

Yoonho Jung, Sang-Wook Yeh + Show 4 more

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https://doi.org/10.1038/s41598-021-04310-8

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Abstract

The significance of long-term teleconnections derived from the anomalous climatic conditions of El Niño has been a highly debated topic, where the remote response of coastal hydrodynamics and marine ecosystems to El Niño conditions is not completely understood. The 14-year long data from a ship-borne acoustic Doppler current profiler was used to examine the El Niño’s impact, in particular, 2009 and 2015 El Niño events, on oceanic and biological processes in coastal regions across the Korea/Tsushima Strait. Here, it was revealed that the summer volume transport could be decreased by 8.7% (from 2.46 ± 0.39 to 2.24 ± 0.26 Sv) due to the anomalous northerly winds in the developing year of El Niño. Furthermore, the fall mean volume backscattering strength could be decreased by 1.8% (from − 97.09 ± 2.14 to − 98.84 ± 2.10 dB) due to the decreased surface solar radiation after the El Niño events. Overall, 2009 and 2015 El Niño events remotely affected volume transport and zooplankton abundance across the Korea/Tsushima Strait through climatic teleconnections.

Highlights

Climate change has major effects on atmospheric and oceanic conditions, leading to changes in precipitation, wind, and ocean c urrents[1,2]
This study examined the effects of two El Niño events, which occurred in 2009 and 2015, on the seasonal and interannual variability in volume transport and mean volume backscattering strength (MVBS) from a ship-borne acoustic Doppler current profiler (ADCP) across the Korea/Tsushima Strait (KTS; Fig. 1) as a proxy for coastal hydrodynamics and ecosystems
The ADCP and climate data were mostly correlated with NINO3 with a 0 to 9-month lag (Supplementary Table 1)

Summary

Introduction

Climate change has major effects on atmospheric and oceanic conditions, leading to changes in precipitation, wind, and ocean c urrents[1,2]. Ref.[10] suggested that the typhoon-dependent nutrient supply largely regulates the abundance and composition of the phytoplankton assemblages These studies were generally based on short-term (< 2 years) observations rather than long-term monitoring e fforts[10]. Volume transport and zooplankton abundance potentially depend on the poorly understood interplay between oceanic processes and climate systems, and require an in-depth understanding of the impact of El Niño on the local weather and marine ecosystems. This study examined the effects of two El Niño events, which occurred in 2009 and 2015, on the seasonal and interannual variability in volume transport and mean volume backscattering strength (MVBS) from a ship-borne acoustic Doppler current profiler (ADCP) across the Korea/Tsushima Strait (KTS; Fig. 1) as a proxy for coastal hydrodynamics and ecosystems. Seasonal comparisons with NINO indices and climate signals were applied to determine the remote impacts of El Niño on the temporal variability in the ADCP data

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