M161 Continuous In-situ Water Vapor Isotopic Composition

<p>A Picarro L2130-i cavity ring-down spectrometer was deployed aboard the Research Vessel Meteor during M161 cruise of the EUREC4A field campaign. Measurements were taken nearly continuously from Jan 18th – Feb 21st 2020 in an area of the North Atlantic typically a few hundred kilometers east of Barbados. Relatively undisturbed air was sampled via an inlet placed at ~25.8 m above the mean sea surface with a forward-facing fetch (above the bow). Air then passed through an inlet line of 505 cm length which was heated to prevent condensation. Periods with winds between 120 and 250 degrees relative to the bow were excluded (masked) to avoid contamination by ship emissions. Daily calibration runs were done throughout the cruise using a rotation of four reference standards. Post-processing included concentration dependence corrections and VSMOW-SLAP normalization. Missing data points due to instrument issues, calibration runs, wind mask are filled with value 9.969209968386869e+36.</p>