The temperature of the surface of the world's oceans provides a clear indication of the state of the Earth's climate and weather. The sea surface temperature anomaly, or difference from the mean, can show climate indicators such as the El Niño oscillation, which manifests as a warmer-than-normal sea surface temperature in the Pacific Ocean west of Ecuador and Peru. This sequence shows a slight La Niña effect, or cooler-than-normal sea surface temperature in the eastern Pacific.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 22.214.171.124.0