Significant wave height fusing multi-mission altimetry and WW3 hindcast

However, their sparse spatial and temporal sampling introduces undersampling errors in wave climate analyses. Direct gridding of multi-mission altimeter data through spatiotemporal interpolation still results in low-accuracy global SWH fields due to this limitation.

To overcome this challenge, we use SWH outputs from a WAVEWATCH III hindcast as a background field and apply an offline post-fusion with along-track, jointly calibrated altimeter observations from the Climate Change Initiative Sea State dataset. Unlike data assimilation within numerical wave models, this offline fusion approach allows retrospective correction of past model outputs using future observations. Validation against buoy measurements and independent satellite data demonstrates that the fused gridded product achieves high accuracy.