Changes in biological productivity associated with Ningaloo Niño/Niña events in the southern subtropical Indian Ocean in recent decades

Recent decades have seen a notable increase in the frequency of Ningaloo Niño events, linked to the cold phase of the Pacific Decadal Oscillation (PDO), which has significantly altered biological productivity in the southern subtropical Indian Ocean. These events, characterized by positive sea surface temperature anomalies off western Australia during Ningaloo Niño and negative anomalies during Niña, disrupt the seasonal cycle of chlorophyll—a key indicator of productivity. The study, utilizing long-term simulations from an ocean-biogeochemical coupled model, reveals that the Leeuwin Current's southward advection during these events plays a crucial role in shaping the spatiotemporal response of chlorophyll. Consequently, there has been an anomalous decrease in productivity during the Austral summer, underscoring the far-reaching ecological impacts of climate oscillations.

Narayanasetti, S., Swapna, P., Ashok, K., Jadhav, J., & Krishnan, R. (2016). Changes in biological productivity associated with Ningaloo Niño/Niña events in the southern subtropical Indian Ocean in recent decades. Scientific Reports, 6(1). https://doi.org/10.1038/srep27467