Presented at the Global Ocean Salinity and the Water Cycle WorkshopThe newly developed NCEI Thermosalinograph Dataset (NCEI-TSG) is the worldâs most extensive collection of uniformly-formatted, quality-controlled, thermosalinograph (TSG) data available without restriction. TSG data are in-situ high resolution measurements of sea surface salinity (SSS) and temperature (SST) from ships. Measurements of other oceanographic variables, such as oxygen, chlorophyll etc are often measured concurrently with sea surface salinity and temperature and included in the dataset. The NCEI-TSG contains observations of TSG from more than 330 ships from 1989 to present. Compared to other datasets, the NCEI-TSG has several advantages: 1) It is the most complete TSG dataset, containing all data from the major TSG data assembly centers with more historical data from NCEIâs archive to be added. 2) When different versions of a dataset are available, the dataset with the highest resolution is always chosen. 3) All data are converted to common netCDF4 format, following Climate and Forecast (CF) and Attribute Convention for Data Discovery (ACDD) conventions. 4) All data are processed using the same 11-step quality control procedures and criteria and flagged using a two-level flag system to provide a well-organized, uniformly quality-controlled TSG dataset for the user community. The NCEI-TSG serves as a significant resource for establishing match-ups with satellite SSS and SST observations for validation and comparisons. It will significantly contribute to the in situ component of the NOAA Satellite SSS Quality Monitor (4SQM) project (under development). This dataset facilitates assessments of global SST and SSS variability and the analysis of patterns and trends at various regional and temporal scales, enabling new insights in climate change, the global water cycle, air-sea interaction, etc. The NCEI-TSG database is freely accessible via the NCEI thredds server and will be maintained with newly received TSG data, as well as further expanded with more historical data from NCEI archive.