Column-averaged dry-air mole fractions of CO2, CH4, and CO from direct sunlight measurements above the Pacific during the MORE-2 campaign 2019

Measurements of atmospheric column-averaged dry-air mole fractions of carbon dioxide (XCO2), methane (XCH4), and carbon monoxide (XCO) have been collected across the Pacific ocean during the Measuring Ocean REferences 2 (MORE-2) campaign in June 2019. We deployed a ship-going variant of the EM27/SUN Fourier Transform Spectrometer (FTS) on board the German research vessel 'Sonne' which, during MORE-2, crossed the Pacific ocean from Vancouver, Canada, to Singapore. Equipped with a custom-built fast solar tracker, the FTS operated in direct-sun view during the ship cruise reliably delivering solar absorption spectra in the shortwave infrared spectral range 4000 to 11000 1/cm. After filtering and bias correcting the dataset, we report on XCO2, XCH4, and XCO measurements for 19 days along a trajectory that largely aligns with 30° N of latitude between 140° W and 120° E of longitude. The dataset has been adjusted to the TCCON (Total Carbon Column Observing Network) station in Karlsruhe, Germany, before and after the MORE-2 campaign through side-by-side measurements. During the campaign the precision for hourly means is found 0.24 ppm, 1.1 ppb, and 0.75 ppb for XCO2, XCH4, and XCO, respectively.