The Indian dipole

Global warming has been called by a number of different terms in recent years: global heating, climate crisis and Hothouse Earth, for example. These terms suggest that ‘warming’ might be too ’soft’ a term and may ignore the fact that in many places, there is a significant rise in temperature, hence ‘heating’. One example is the rise in temperatures in the Indian Ocean which may be linked to the bush-fires in Australia and flooding in parts of Africa.

The Indian Ocean Dipole refers to temperature change in the Indian Ocean which leads to extreme events in Australia and Africa. Due to global climate change, the western Indian Ocean warms up more than the eastern Indian Ocean. This affects atmospheric circulation and precipitation in the two regions. The warmer western ocean experiences more rainfall, such as that which affected parts of Africa this year. The cooler eastern ocean experiences less rainfall, leading to drought and extreme fire conditions in parts of Australia.

It is similar to the reversals caused by El Nino in the Pacific Ocean, which cause pronounced weather reversals in South America and Australia. Unlike the Pacific Ocean and the Atlantic Ocean which are able to disperse warmer water through ocean currents, the Asian land landmass prevents this.

There is evidence that the Indian Dipole has become more frequent and more intense as the ocean has warmed up over the last 50 years. It is predicted that if the Dipole intensifies, there will be more fires over Australia and more intense floods in Africa. The floods there affected 2.5 million people this year. Around lake Turkana in Kenya around 30% of the population are said to be affected by malnutrition, and the floods badly affected crop growth.

More information:

• The Indian dipole https://en.wikipedia.org/wiki/Indian_Ocean_Dipole
• Sub-Tropical Indian Dipole https://en.wikipedia.org/wiki/Subtropical_Indian_Ocean_Dipole