Bureau of Meteorology (BOM) researchers are pushing for a reevaluation of how El Niño and La Niña events are classified.

This year's El Niño declaration was delayed, leading to confusion, as the BOM moved to ‘El Niño Alert’ in June, but the official declaration came in September, while other agencies had already declared it.

BOM climate researcher Matthew Wheeler has co-authored a report suggesting changes to the classification system due to global ocean warming, which makes it easier to trigger El Niño but potentially harder for La Niña to occur.

The proposal recommends adopting the Relative Niño 3.4 index, which considers global tropical ocean anomalies. 

This shift could have changed the timing of this year's El Niño declaration to better match atmospheric responses.

The BOM and other agencies are considering these changes to align El Niño and La Niña declarations and reduce discrepancies.

While public interest in these events is increasing, experts suggest relying more on long-range seasonal outlooks for accurate climate predictions, especially in a changing climate. 

More details are accessible here.