Global Wave Hindcasts Using the Observation‐Based Source Terms: Description and Validation

Global wave hindcasts are developed using the third generation spectral model WAVEWATCH III with observation-based source terms (ST6) and a hybrid rectilinear-curvilinear, irregular-regular-irregular grid system (approximately at ). Three distinct global produced: (a) long-term hindcast (1979–2019) forced by ERA5 conventional winds (b) two short-term (2011–2019) driven NCEP climate forecast (CFS)v2 neutral , respectively. The input field for ice is sourced from Ocean Sea Ice Satellite Application Facility (OSI SAF) sea-ice concentration data records. These simulations, together driving wind forcing, validated against extensive in-situ observations satellite altimeter performance of ST6 shows promising results across multiple parameters, including characteristics (e.g., height period) high-order moments surface Stokes drift mean square slope). ERA5-based simulations generally present lower random errors, but CFS-based run represents extreme sea states m) considerably better. Novel parameters available in our hindcasts, namely dominant breaking probability, wave-induced mixed layer depth, freak indexes wave-spreading factor, further described briefly discussed. Inter-comparisons (41 years) hindcast, buoy measurements different calibrated sets highlight inconsistency these records arising calibration methodology. Significant errors low-frequency bins (period s) both energy directionality call development.