Indian Ocean’s neutral temperatures signals relief for Namibia

The Indian Ocean Dipole (IOD) has entered a neutral phase, a trend that is expected to persist throughout the spring, according to an August 18, 2024, statement from the Australian Government’s Bureau of Meteorology. 

This shift is viewed as a positive development, offering respite from the previous positive IOD event, which, coupled with the El Niño declared in September 2023, contributed to one of the driest rainy seasons Southern Africa has seen in recent years.

The recent positive IOD, which peaked at +1.92°C in October 2023, was the second strongest on record, just behind the 2019 event that reached +2.15°C. The IOD plays a crucial role in influencing climate patterns across Southern Africa and Australia, significantly impact-ing rainfall conditions.

Typically, a positive IOD, characterized by warmer sea surface temperatures, leads to drier conditions, while a negative IOD, marked by cooler temperatures, brings enhanced rainfall to Southern Africa. The current neutral IOD, expected to have minimal impact on rainfall patterns, is preferable to a positive IOD that could result in warmer ocean waters and potentially more tropical cyclones.

Meanwhile, international scien-tists are also monitoring the potential development of a La Niña event, although it is expected to be weak. 

The National Oceanic and Atmospheric Administration (NOAA) recently issued a La Niña watch, signaling that conditions are favorable for La Niña to develop within the next six months. While the current forecast suggests that ENSO-neutral conditions will likely continue in the coming months, NOAA estimates a 66% chance of La Niña emerging between September and November, with a 74% probability of it persisting through the southern hemisphere summer of 2024-25.

La Niña, along with El Niño, forms part of the natural climate cycle known as the El Niño–Southern Oscillation (ENSO).