Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java sea

Intense mesoscale eddy activity has been observed off the southern Java coast (SJC), yet its impact on local ecosystems remains largely unknown. To investigate this, we examined remotely sensed altimetry, chlorophyll-a (Chl-a), and sea surface temperature (SST) data, focusing on their response to ed...

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Main Authors: Azis Ismail M.F., Budiman A.S., Basit A.
Format: Article
Language:English
Published: Elsevier 2024-10-01
Series:Kuwait Journal of Science
Subjects:
Online Access:https://www.sciencedirect.com/science/article/pii/S2307410824000786
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author Azis Ismail M.F.
Budiman A.S.
Basit A.
author_facet Azis Ismail M.F.
Budiman A.S.
Basit A.
author_sort Azis Ismail M.F.
collection DOAJ
description Intense mesoscale eddy activity has been observed off the southern Java coast (SJC), yet its impact on local ecosystems remains largely unknown. To investigate this, we examined remotely sensed altimetry, chlorophyll-a (Chl-a), and sea surface temperature (SST) data, focusing on their response to eddies in the region. Our eddy detection and tracking analysis revealed a unique cyclonic frontal eddy near the SJC coast and a large anticyclonic eddy offshore, active from July to September 2019. The cyclonic frontal eddy induced water transport through eddy filaments, upwelled subsurface cold water, and enhanced Chl-a concentrations by horizontally entraining Chl-a-rich shelf water offshore. The anticyclonic eddy then contributed to further distributing this enriched water southward. The mean cross-shelf transport associated with the frontal eddy was estimated at 1.80–2.33 Sv offshore, exporting approximately 1.87–2.40 × 103 tons of Chl-a to the Indian Ocean during its lifetime. Additionally, the spatial cross-correlation analysis of zonal and meridional wind stress with Chl-a revealed relatively high correlation values (0.6–1) and short lag times (<5 days) in offshore areas, indicating that the role of wind in the Chl-a advection cannot be ignored. We propose a three-stage mechanism to explain the presence of high Chl-a offshore:1) Wind-driven upwelling intensifies coastal nutrients, elevating Chl-a concentrations in coastal waters, 2) Frontal cyclonic eddy facilitates the retention and offshore export of these upwelling-enriched waters. and 3) Anticyclonic eddy advects these nutrient-rich waters further south. The combination of enhanced coastal upwelling and eddies can explain nutrient-rich coastal waters in offshore regions. © 2024 The Authors
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spelling doaj-art-1402c9c0489e47fe8aafa52431040b952025-08-20T03:22:03ZengElsevierKuwait Journal of Science2307-41082307-41162024-10-0151410025310.1016/j.kjs.2024.100253Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java seaAzis Ismail M.F.Budiman A.S.Basit A.Intense mesoscale eddy activity has been observed off the southern Java coast (SJC), yet its impact on local ecosystems remains largely unknown. To investigate this, we examined remotely sensed altimetry, chlorophyll-a (Chl-a), and sea surface temperature (SST) data, focusing on their response to eddies in the region. Our eddy detection and tracking analysis revealed a unique cyclonic frontal eddy near the SJC coast and a large anticyclonic eddy offshore, active from July to September 2019. The cyclonic frontal eddy induced water transport through eddy filaments, upwelled subsurface cold water, and enhanced Chl-a concentrations by horizontally entraining Chl-a-rich shelf water offshore. The anticyclonic eddy then contributed to further distributing this enriched water southward. The mean cross-shelf transport associated with the frontal eddy was estimated at 1.80–2.33 Sv offshore, exporting approximately 1.87–2.40 × 103 tons of Chl-a to the Indian Ocean during its lifetime. Additionally, the spatial cross-correlation analysis of zonal and meridional wind stress with Chl-a revealed relatively high correlation values (0.6–1) and short lag times (<5 days) in offshore areas, indicating that the role of wind in the Chl-a advection cannot be ignored. We propose a three-stage mechanism to explain the presence of high Chl-a offshore:1) Wind-driven upwelling intensifies coastal nutrients, elevating Chl-a concentrations in coastal waters, 2) Frontal cyclonic eddy facilitates the retention and offshore export of these upwelling-enriched waters. and 3) Anticyclonic eddy advects these nutrient-rich waters further south. The combination of enhanced coastal upwelling and eddies can explain nutrient-rich coastal waters in offshore regions. © 2024 The Authorshttps://www.sciencedirect.com/science/article/pii/S2307410824000786chlorophyll-across-shelf fluxmesoscale eddiessea surface temperature (sst)upwelling filament
spellingShingle Azis Ismail M.F.
Budiman A.S.
Basit A.
Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java sea
Kuwait Journal of Science
chlorophyll-a
cross-shelf flux
mesoscale eddies
sea surface temperature (sst)
upwelling filament
title Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java sea
title_full Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java sea
title_fullStr Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java sea
title_full_unstemmed Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java sea
title_short Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java sea
title_sort cross shelf transport of high chlorophyll a coastal waters by frontal eddies in the south of java sea
topic chlorophyll-a
cross-shelf flux
mesoscale eddies
sea surface temperature (sst)
upwelling filament
url https://www.sciencedirect.com/science/article/pii/S2307410824000786
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AT budimanas crossshelftransportofhighchlorophyllacoastalwatersbyfrontaleddiesinthesouthofjavasea
AT basita crossshelftransportofhighchlorophyllacoastalwatersbyfrontaleddiesinthesouthofjavasea