Contrasting tropical precipitation and ecosystem response to Indian Ocean Dipole in a warming climate.

The Indian Ocean Dipole (IOD) significantly influences tropical precipitation patterns, with its positive phase triggering severe floods and droughts in Indian Ocean rim countries. These climate extremes are projected to intensify under global warming. However, how the IOD will modulate the tropical precipitation and ecosystem response under warming climate remains unknown.

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

Using observations and long term simulations of an ocean-biogeochemical coupled model, we investigate the biological response in the southern subtropical Indian Ocean (SIO) associated with Ningaloo Niño and Niña events. Ningaloo events have large impact on sea surface temperature (SST) with positive SST anomalies (SSTA) seen off the west coast of Australia in southern SIO during Ningaloo Niño and negative anomalies during Niña events. Our results indicate that during the developing period of Ningaloo Niño, low chlorophyll anomaly appears near the southwest Australian coast concurrently with high SSTA and vice-versa during Niña, which alter the seasonal cycle of biological productivity.