Explanation:

The Indian Ocean Dipole (IOD) is often called the "Indian Niño" because of its similarity to its Pacific equivalent. It refers to the difference in sea-surface temperatures in opposite parts of the Indian Ocean.

Positive IOD (Arabian Sea warmer than Bay of Bengal) results in more cyclones than usual in Arabian Sea.

• While Negative IOD results in stronger than usual Tropical Cyclones in the Bay of Bengal. Cyclonic activity in Arabian Sea is suppressed.
• Indian Ocean Dipole(IOD) effect demonstrated that a positive IOD index often negated the effect of El Nino, resulting in increased Monsoon rains in several El Nino years like the 1983, 1994 and 1997.
• Two poles of the IOD – the eastern pole (around Indonesia) and the western pole (off the African coast) were independently and cumulatively affecting the quantity of rains for the Monsoon in the Indian subcontinent.

Hence only statement 1st is correct.