Global marine deflection of the vertical and gravity anomaly models derived from ICESat-2 laser altimeter data:SDUST2024DOV­_IS2 and SDUST2024GRA_IS2

This dataset provides global 1-arcminute gridded models of marine free-air gravity anomalies and deflections of the vertical (DOV) derived from ICESat-2 laser altimetry. The products cover the global oceans from 80°S to 88°N and longitudes from 0° to 360°E, referenced to the GRS80 ellipsoid.<b>To ensure FAIR compliance and adhere to the Climate and Forecast (CF) Metadata Conventions, both NetCDF files include a machine-readable crs</b><b> (coordinate reference system) variable.</b> This grid_mapping variable explicitly encodes the exact GRS80 ellipsoid parameters (semi-major axis = 6378137.0 m; inverse flattening = 298.257222101).The file <b>SDUST2024GRA_IS2.nc</b> contains the global marine gravity anomaly model on a 1′ × 1′ grid. It includes four variables:<i> lon</i> and <i>lat</i> (one-dimensional coordinate vectors), <i>crs</i> (the grid mapping variable), and <i>gra</i> (a 10080 × 21600 array representing marine gravity anomalies in milligals, mGal).The file <b>SDUST2024DOV_IS2.nc</b> provides the global marine deflection of the vertical model on the same spatial grid. It includes five variables:<i> lon, lat, crs, dov_ns</i> (meridional component), and <i>dov_ew</i> (prime-vertical component). The DOV arrays have the same dimensions as the gravity anomaly grid, and all values are reported in microradians (µrad).The models were derived exclusively from ICESat-2 ATL12 photon data. We implemented an optimized fusion strategy that combines the meridional component estimated from along-track geoid gradients with the prime-vertical component estimated from cross-track geoid gradients, yielding a directionally balanced DOV model. This fusion improves component-wise accuracy and enhances the stability and overall accuracy of the gravity anomaly inversion.<b>Uncertainty and Validation:</b> The accuracy of the data products has been rigorously assessed using independent validation datasets. The marine gravity anomaly model (SDUST2024GRA_IS2) was validated against NCEI shipborne gravity measurements, achieving a global standard deviation of approximately 5.71 mGal. For the deflection of the vertical (SDUST2024DOV_IS2) model, the estimated uncertainty is characterized by standard deviations of 3.34 µrad for the meridional component and 3.69 µrad for the prime-vertical component, as evaluated against the SIO V32.1 benchmark.<b>Code Availability:</b> The code for data processing is available on GitHub: https://github.com/XinLiu1969/Calculate-DOV-and-gravity-anomalies"