Assessment of Ocean Tide Modeling Based On ICESat-2 Data

ICESat-2 space-borne LIDAR data now extends for over a year. Over oceans, strong beam data are investigated to assess the quality of several existing global tide models, concentrating on a few regions where the models are known to diverge. Over ice-covered regions, notably the floating Antarctic ice shelves, strong and/or weak-beam data can be used, as appropriate. We primarily employ variance reduction tests, as Padman and Fricker did many years ago with ICESat-1 data. Over the Weddell Sea, Zaron's recent tidal solutions, based mostly on Cryosat-2 data, are also compared. In a few locations where tidal wavelengths are sufficiently broad, time series can be analyzed to more directly assess individual constituents, even though one year of data is too short for detailed analysis. Owing to the slow ICESat-2 precession rate of 0.27°/day, the sidereal constituents K1 and K2 are poorly resolved (similar to the situation with Cryosat-2) and little can be said yet, but the lunar tides are mostly well resolved.