The global lens used to follow El Nino has become a bit less accurate after Japan cut by about half the number of buoys in the Western Pacific that monitor changes in the ocean. It will take another four to five offline next year.

Data collected by the anchored buoys include wind measurements, air and water temperatures, currents, and the salinity of the ocean, which are then transmitted to satellites in near real time. The system can look down about 2,500 feet into the Pacific, according to the Japan Agency for Marine-Earth Science and Technology.

The cuts by Japan are "a major issue," said Kevin Trenberth, a distinguished senior scientist at the National Center of Atmospheric Research in Boulder, Colorado. "There is a task group that has been meeting and planning for how to proceed to monitor the tropical Pacific Ocean."