Authors / CoAuthors
Xie, S. | Huang, Z. | Wang, X.
Abstract
The East Australian Current (EAC) onshore encroachment drives coastal upwelling and shelf circulations, changes slope-shelf bio-physical dynamics, and consequently exerts significant influence on coastal marine ecosystem along the south-eastern Australian margin. The EAC is a highly dynamic eddy-current system which exhibits high-frequency intrinsic fluctuations and eddy shedding. As a result, low-frequency variability in the EAC is usually overshadowed and rarely detectable. For decades, despite many efforts into the ocean current observations, the seasonality of EAC’s shoreward intrusion remains highly disputable. In this study, for the first time we use a long-term (26 years) remotely sensed AVHRR Sea Surface Temperature (SST) dataset spanning 1992-2018 to map the EAC off the coast of northern New South Wales (NSW), between 28°S - 32.5°S. A Topographic Position Index (TPI) image processing technique was applied to conduct the quantitative mapping. The mapping products have enabled direct measurement (area and distance) of the EAC’s shoreward intrusion. Subsequent spatial and temporal analyses have shown that the EAC move closer to the coast in austral summer and autumn than in austral winter, with the mean distance-to-coast ~6 km shorter and occupying the shelf area ~12% larger. This provides quantitative and direct evidence of the seasonality of the EAC’s shoreward intrusion. Such seasonal migration pattern of the EAC thus provides new insights into the seasonal upwelling and shelf circulations previously observed in this region. As a result, we were able to confirm that the EAC is a driving force of the seasonal ocean dynamics for the northern NSW coast.
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document
eCat Id
133044
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
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Keywords
- theme.ANZRC Fields of Research.rdf
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- EARTH SCIENCES
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- satellite remote sensing
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- quantitative mapping
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- spatial analysis
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- the East Australian Current - EAC
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- New South Wales - NSW
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- coastal upwelling
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- shelf circulation
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- Published_External
Publication Date
2023-11-01T05:47:54
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completed
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External publication
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Topic Category
oceans
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remote sensing Volume 13, Issue 5 854
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This manuscript is a result of a research collaboration between GA and UNSW Canberra. The paper is published. Citation: Xie, S., Huang, Z., Wang, X.H., 2021. Remotely Sensed Seasonal Shoreward intrusion of the East Australian Current: Implications for Coastal Ocean Dynamics, Remote Sensing, 13, 854.
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[-44.00, -9.00, 112.00, 154.00]
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