Integrated Water Vapor contents from GNSS observations collected onboard research vessels of the French Oceanographic Fleet

This dataset provides shipborne Integrated Water Vapour (IWV) time series derived from GNSS observations collected onboard research vessels of the French Oceanographic Fleet, operated by Ifremer and its fleet operator subsidiary Genavir. The data span the period 2015–2024, depending on the vessel, and cover major ocean basins through successive oceanographic campaigns.
Zenith Total Delay (ZTD) estimates are obtained from Precise Point Positioning processing of GNSS RINEX files using GipsyX 2.2 (JPL, NASA). ZTD and position estimates are quality-controlled prior to atmospheric retrieval. The Zenith Hydrostatic Delay (ZHD) is computed from ERA5 surface pressure fields provided by ECMWF, following the formulation of Saastamoinen (1972), updated by Bosser et al. (2007). The Zenith Wet Delay (ZWD) is derived as ZTD minus ZHD and converted into IWV following Bosser et al. (2021), using mean atmospheric temperature (Tm) derived from VMF1 grids (Böhm et al., 2006). IWV values are finally extrapolated from the antenna height to mean sea level.
The dataset provides 30 s resolution time series including the following variables: date, latitude, longitude, antenna height above ellipsoid and mean sea level, ZTD, ZHD, Tm, IWV, and associated uncertainties. Data availability is campaign-based and therefore discontinuous in time.
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More information about this dataset and its validation is provided in a dedicated data paper (Panetier et al., 2026, submitted to ESSD).