Scientists have discovered a massive water mass in the Atlantic Ocean called the Atlantic Equatorial Water. This water mass blends distinct water masses along the equator due to ocean currents. The discovery, published in the journal Geophysical Research Letters, completes the understanding of fundamental water masses across the World Ocean. The Atlantic Equatorial Water was identified using data from the Argo program, which consists of self-submerging floats. This finding will enhance scientists' understanding of the ocean's mixing processes and global transport of heat, oxygen, and nutrients.