Answer:
Buoys are defined as a device that is constructed in such a way that it can float on the surface of the water as well as at certain depths and used for various purposes, such as weather variables that describes the height of a wave, speed of the wind and its direction of motion, calculates the temperature of both air and water and the barometric pressure also is determined using this device. They are mostly connected to a number of sensors that are directly connected to the weather stations and satellites that records (measures) all of its water and air parameters.
Thus, buoys records El Nino and also it transmits data to the satellites that are in space.