The HIPPO.ORNL.GOV website has transitioned to EOL UCAR. Data and documentation are available at https://www.eol.ucar.edu/field_projects/hippo.
The HIPPO (HIAPER Pole-to-Pole Observations) study of the carbon cycle and greenhouse gases measured meteorology, atmospheric chemistry, and aerosol constituents along transects from approximately pole-to-pole over the Pacific Ocean. More info..