Data were collected between May 28, 2017 and June 13, 2017 using an equilibrated inlet mass spectrometer (EIMS, Cassar et al., 2009) connected to the surface uncontaminated seawater supply of the Research Vessel Marcus G. Langseth on Cruise ID MGL1704. Data were collected near-continuously over the cruise track which departed and returned from Honolulu, HI and sampled waters of the North Pacific subtropical gyre and transition zone. The xls file ‘MGL1704_Gradients2_Surface_O2Ar_NCP.xls’ and companion ASCII text file ‘MGL1704_Gradients3_Surface_O2Ar_NCP.txt’ contain columns for UTC date/time (yyyy-mm-ddTHH:MM:ssZ), Latitude (decimal deg), Longitude (decimal deg), Surface Sea Temperature measured in the wetlab with a SeaBird Thermosalinograph (degrees C), Surface Salinity measured in the wetlab with a Seabird Thermosalinograph (no units), the Saturation of O2 /Ar (O2/Ar measured divided by O2/Ar saturation, %), and the calculated net community production in surface seawater (mmol O2 m-2 d-1). Missing data is indicated by an empty cell.