Dipole Mode Index (DMI)

The Dipole Mode Index (DMI) measures the difference in sea surface temperatures between two regions in the Indian Ocean—specifically, the western and eastern parts. When the western Indian Ocean is warmer than usual, the DMI becomes positive, indicating a strengthening of the Indian Ocean Dipole (IOD). Conversely, a negative DMI suggests the eastern region is warmer. Changes in the DMI influence weather patterns, affecting monsoons, rainfall, and droughts in surrounding areas like Australia, Africa, and Asia. It is a key indicator used by meteorologists to monitor and predict climate variability related to the Indian Ocean.