Ocean cold as water at greater depths. Below the thermocline, water is very cold, ranging from −1 °C to 3 °C. Because this deep and cold layer contains the bulk of ocean water, the average temperature of the world ocean is 3.9 °C. If a zone undergoes dramatic changes in salinity with depth, it contains a halocline. If a zone undergoes a strong, vertical chemistry gradient with depth, it contains a chemocline. The halocline often coincides with the thermocline, and the combination produces a pronounced pycnocline. The deepest point in the ocean is the Mariana Trench, located in the Pacific Ocean
World Ocean Atlas number of data points the average is derived from, their standard deviation and standard error. A lower horizontal resolution (5°) version of the WOA is also available. The WOA dataset is primarily available as compressed ASCII, but since WOA 2005 a netCDF version has also been produced. World Ocean Atlas The World Ocean Atlas (WOA) is a data product of the Ocean Climate Laboratory of the National Oceanographic Data Center (U.S.). The WOA consists of a climatology of fields of "in situ" ocean properties for the World Ocean. It was first produced in 1994 (based on the earlier "Climatological Atlas