Lagrangian backtracked trajectories for YGCW parcels (20-day OceanParcels; NEMO-G108 full-3D velocity field)

CF-1.10 NetCDF containing 20-day backward Lagrangian trajectories used to track the origin of parcels forming the YGCW in the virtual Yucatan section (Figure 4). Trajectories were seeded near the detection region and advected backward with OceanParcels (Delandmeter & Van Sebille, 2019) forced by NEMO-G108. Along-path Absolute Salinity and Conservative Temperature were sampled. In addition, quasi-Eulerian velocities—u_lag, v_lag, w_lag—were estimated from the trajectories (post-processed; not directly sampled) and provided for figure diagnostics. Each column = one trajectory; the observation dimension has 160 samples (20 days at 3-hourly intervals). File & variable format Recommended filename: YGCW_Parcels_Backtracked20d_NEMO-G108.nc Dimensions: obs=160, trajectory=62911 (arrays stored as [obs × trajectory]) Feature type: trajectory (CF) Coordinates (aux variables): time — seconds since 1970-01-01 00:00:00 UTC (gregorian) lat — degrees_north lon — degrees_east depth — meters, positive down Data variables (names/units): SA — Absolute salinity (g kg⁻¹) CT — Conservative temperature (degree_Celsius) u_lag, v_lag, w_lag — velocity estimates from trajectories (m s⁻¹) IDs/coverage: trajectory (int, cf_role="trajectory_id") trajectory_start_time, trajectory_end_time — per-trajectory coverage (s since epoch) MethodsBacktracking performed with OceanParcels using NEMO-G108 outputs; release criteria, temporal resolution, and velocity estimation follow the manuscript and Supporting Information. This file was created with write_parcels_backtrack_cf.m. CoverageRegion: Yucatan Channel and upstream Caribbean pathways (exact extent given in file attributes).Time span: per-trajectory start/end provided; all trajectories are 20 days long. Format & conventionsNetCDF-4 (deflate), CF-1.10; featureType=trajectory; coordinates given in WGS84 (EPSG:4326). LicenseCC-BY 4.0 (processed products). Usage noteVelocities u_lag, v_lag, w_lag are derived from trajectories and may differ from instantaneous Eulerian values. KeywordsYucatan Channel; Lagrangian trajectories; backtracking; OceanParcels; YGCW; submesoscale; CF-NetCDF.