Brian Arbic (University of Michigan, United States); Jay Shriver (Naval Research Laboratory , United States); Edward Zaron (Oregon State University, United States); Maarten Buijsman (University of Southern Mississippi, United States); Loren Carrère (CLS, France); Michel Tchilibou (CLS, France)

Internal tides, which manifest as sub-surface gravity waves with observable sea surface height changes, pose a unique opportunity for the SWOT mission to deepen our understanding of oceanic processes at the mesoscale and submesoscale levels. We assesses the capability of the data-assimilative HYCOM forecast system in accurately identifying and resolving both phase-locked and non-phase-locked internal tides during the both Cal/Val and SCIENCE orbits. We compare HYCOM's performance to the HRET22 model, which is limited to accounting for phase-locked tides. During the SCIENCE orbit, HYCOM globally captures 20% more sea surface height variance related to phase-locked internal tides compared to HRET22, highlighting its enhanced predictive capability. The key advantage of using HYCOM lies in its proficiency at predicting non-phase-locked component of internal tides, where it accounts for an additional 30% of the variance. During Cal/Val period, HYCOM effectively reduces up to 60% of the total variance for phase-locked tides and further minimizes 10-20% of non-phase-locked signals in SWOT observations at the M2 frequency. Forecast models uniquely address the challenge of predicting both phase-locked and non-phase-locked parts by effectively enhancing internal tide mapping, leading to significant improvements in altimetric data correction in the SWOT-era of oceanography.