Global ocean synoptic thermocline gradient, isothermal-layer depth, and other upper ocean parameters

Abstract Different from the existing global ocean climatological datasets of isothermal layer (ITL) depth ( h ), a global ocean synoptic dataset of h along with other parameters has been established from temperature profiles of the National Centers for Environmental Information (NCEI) world ocean database 1961–2017. The exponential leap-forward gradient method was used to identify h and thermocline gradient ( G ) from each temperature profile measured by expendable bathythermograph (XBT) and conductivity, temperature, depth (CTD) instruments. Due to quality and vertical resolution of the profiling data, the numbers of ( G , h ) pairs are 446,811 out of 964,942 CTD profiles and 755,086 out of 2,303,433 XBT profiles. With the given h , other parameters such as ITL heat content ( H ITL ), sea surface temperature ( SST ), temperature below ITL ( T m ), and quality measures ( Q , I ) indices are provided. Altogether, the dataset contains 1,201,897 temporally and horizontally varying sets of ( G , h , H ITL , SST, T m , Q -index, I- index). Note that we added 200° to the longitude. This synoptic dataset is located on the NCEI website for public use.