Illustration linking the Indian Ocean and the monsoons

Surface temperatures in the Indian Ocean naturally oscillate, a phenomenon called the Indian Ocean Dipole. During its positive phase, warmer waters in the western Indian Ocean bring heavy rains to East Africa and India, and colder waters bring drought to Southeast Asia. In the negative phase, ocean and monsoonal conditions reverse. To better understand the complexities of the monsoon system, WHOI researchers are studying clues from the past using tiny seafloor shells whose chemistry can reveal ocean temperatures that existed tens of thousands of years ago. (Illustration by E. Paul Oberlander, Woods Hole Oceanographic Institution, © Woods Hole Oceanographic Institution)