This data set contains North Pole Environmental Observatory (NPEO) Aerial CTD Survey data. It includes conductivity, temperature, depth (CTD), pressure, salinity, potential temperature, and density data, which were collected yearly in the Arctic Ocean as part of the NPEO. Investigators landed a helicopter or skiplane on the arctic sea ice and took measurements using a Seabird SBE-19 SeaCAT with a portable winch. They processed the data using the SEASOFT recipe to minimize salinity spiking and correct for a thermal lag of the conductivity cell. Certain constants were determined by empirical trial, which differed slightly for each year.

The NPEO is a year-round, automated scientific observatory, deploying various instruments each April in order to learn how the world's northernmost sea helps regulate global climate. It consists of a set of unmanned scientific platforms that record oceanographic, cryospheric, and atmospheric data throughout the year. More information about the project is available at the project Web site. NPEO data are in tab-delimited ASCII text format.