FN Archimer Export Format PT J TI Global wave height trends and variability from new multi-mission satellite altimeter products, reanalyses and wave buoys BT AF Timmermans, B.W. Gommenginger, C.P. Dodet, Guillaume Bidlot, J.-R. AS 1:1;2:1;3:2;4:3; FF 1:;2:;3:PDG-ODE-LOPS-SIAM;4:; C1 National Oceanography Centre, European Way; Southampton, United Kingdom Laboratoire d'Océanographie Physique et Spatiale (LOPS), CNRS, IRD, Ifremer, IUEM, Univ. Brest, France European Centre for Medium-Range Weather Forecasts; Reading,United Kingdom C2 NOC, UK IFREMER, FRANCE ECMWF, UK SI BREST SE PDG-ODE-LOPS-SIAM UM LOPS IN WOS Ifremer UMR copubli-europe IF 4.72 TC 67 UR https://archimer.ifremer.fr/doc/00622/73371/72562.pdf https://archimer.ifremer.fr/doc/00622/73371/72563.pdf https://archimer.ifremer.fr/doc/00622/73371/72564.pdf LA English DT Article DE ;Sea state;Wave height;Trends;Altimetry;Satellite wave observations;Dataset intercomparison AB Long‐term changes in ocean surface waves are relevant to society and climate research. Significant wave height climatologies and trends over 1992‐2017 are intercompared in four recent high‐quality global datasets using a consistent methodology. For two products based on satellite altimetry, including one from the European Space Agency Climate Change Initiative for Sea State, regional differences in mean climatology are linked to low and high sea states. Trends from the altimetry products, and two reanalysis and hindcast datasets, show general similarity in spatial variation and magnitude but with major differences in equatorial regions and the Indian Ocean. Discrepancies between altimetry products likely arise from differences in calibration and quality control. However, multi‐decadal observations at two buoy stations also highlight issues with wave buoy data, raising questions about their unqualified use, and more fundamentally about uncertainty in all products. Plain Language Summary Changes to ocean waves over decades and longer are of considerable importance to climate, society and the marine economy. Accurate observations of waves spanning many decades are required to understand long‐term changes, but the challenges and cost of measuring waves worldwide with devices like buoys means that alternatives like Earth‐orbiting satellites become attractive. We compare two recently published global wave products derived from the same satellite observations, with two high quality products from computer simulations, and buoy measurements. Using a consistent methodology, we find important differences between the satellite products, and the simulations, in the reported average global wave conditions, and their evolution in time. The disagreement between the satellite products points to complex differences in the way satellite data are corrected, which raises questions about uncertainty in these products, and more generally, about what is our most reliable long‐term observational record of sea state. PY 2020 PD MAY SO Geophysical Research Letters SN 0094-8276 PU American Geophysical Union (AGU) VL 47 IS 9 UT 000536639500041 DI 10.1029/2019GL086880 ID 73371 ER EF