Mechanisms for Generation and Development of the Ningaloo Niño

A significant discovery in understanding the Ningaloo Niño phenomenon reveals that northerly wind anomalies off Western Australia play a pivotal role in generating warm sea surface temperature (SST) anomalies. These winds reduce turbulent heat loss, enhance the Leeuwin Current's heat transport, and weaken coastal upwelling, contributing to SST warming. Additionally, these wind anomalies suppress cold dry air transport from the Southern Ocean, further reducing heat loss. A positive cloud–radiation feedback also amplifies SST warming by increasing downward solar radiation. The study, using ocean and atmospheric general circulation model experiments, found that approximately 40% of Ningaloo Niño events between 1950 and 2010 coincided with La Niña, while 30% occurred with a positive Indian Ocean dipole (IOD). Notably, around 30% of these events were independent of both La Niña and IOD, highlighting the complexity and multifaceted nature of the phenomenon.

Zhang, L., Han, W., Li, Y., & Shinoda, T. (2018). Mechanisms for Generation and Development of the Ningaloo Niño. Journal of Climate, 31(22), 9239–9259. https://doi.org/10.1175/jcli-d-18-0175.1