TIDE for Research and Operational Oceanography

TIDE is a client layer over operational forecast and observational products, designed for scientific use: honest uncertainty, explicit conventions, provenance-first attribution, and access to the underlying fields without abstraction.

• National and regional hydrographic institutes
• Research centres with operational forecasting mandates
• University coastal-modelling and physical-oceanography groups
• Civil protection scientific advisory offices

• Native support for HF-radar UV products (WERA, CODAR, and other installations via standard NetCDF).
• Reads the combined u/v covariance fields (P_uu, P_vv, P_uv) delivered alongside the total-current product by the manufacturer software (WERA / CODAR), derived from the per-station radial variances through the known station geometry (cf. Lipa & Barrick 1983; Graber et al. 1997). TIDE propagates them analytically into speed uncertainty via the exact first-order formula:

σ_speed² = (u²·P_uu + v²·P_vv + 2·u·v·P_uv) / (u² + v²)

• Station-radial products with per-point σ derived from sigma2_s*.
• Meteogram shows radial velocity time series with error bands derived by analytical covariance propagation - segment-based drawing breaks at NaN so gap artefacts do not form malformed polygons.

• Separate drifter backend polls feeds per campaign, persists to DB, serves thin JSON to the frontend.
• Quality control applied at ingest: 3 m/s ceiling (western-boundary currents + Stokes + windage) with 1.8 km floor to suppress false positives on short gaps. Flagged, never deleted.
• Auto-thinning preserves the M2 tidal ellipse (12.42 h period) - thinning interval capped at 3600 s for analysis windows ≥ 72 h.
• DSGVO-compliant architecture: email identifiers stored only as HMAC-SHA256 (salt ≥ 32 chars); daily retention pruning; magic-link authentication.
• Administrative tool to re-run QC idempotently after threshold changes.

• On-the-fly rasterisation for SCHISM, FVCOM, and FESOM output.
• Demonstrated with publicly available regional SCHISM output at mesh edges down to ~5 m in coastal domains (effective physical resolution ~5-10× edge length after the linear FE basis; cf. Lemarié et al. 2012), with smooth browser interaction via a Go caching backend.
• Standard input formats (NetCDF, GRIB). No offline pre-processing required.

• Time series at any map location for all integrated layers (wind, currents, waves, HF radar).
• Per-model uncertainty visualisation:
  • NWP layers: synthetic sqrt(Δt) error growth for horizon illustration
  • HF-radar UV: covariance-propagated σ_speed (above)
  • HF-radar radials: √(sigma2) per point
• Bracketing-pair temporal interpolation on u/v components (never on magnitude/direction), avoiding the 0°/360° wrap artefact by construction in UV mode.

• Timestamps: UTC, ISO 8601.
• Coordinates: WGS-84, 4-decimal precision (GPS-grade, ~11 m).
• Wind direction: FROM (meteorological convention).
• Current direction: TO (oceanographic convention).
• Wave direction: FROM (WMO Code Table 0877).
• Stokes drift direction negated from MWD per Phillips (1977): U_s = 2π³Hs²/(gTp³).
• Speeds in m/s; cm/s available on request for drifter-velocity outputs.
• Nodata sentinel: -9999 on backend, NaN on client.

• TIDE performs no data assimilation. Forecast skill is inherited from upstream products.
• Temporal interpolation is applied to u/v components, never to magnitude or direction. This avoids the 0°/360° wrap artefact by construction. Data products supplied as (magnitude, direction) are decomposed to u/v before interpolation and recomposed for display.
• Uncertainty communication: synthetic for NWP horizon, analytical for HF radar. Methods labelled explicitly in plots.

• Source code: available to collaborators on request; deployment commits pinned to tagged releases.
• Data-licence acknowledgements required in derivative publications:
  • Copernicus Marine Service: "Generated using E.U. Copernicus Marine Service Information; https://doi.org[product-specific DOI]"/.
  • ECMWF Open Data: attribution under CC-BY 4.0; cite product and cycle (e.g. "IFS HRES").
  • DWD OpenData: attribution "© Deutscher Wetterdienst" under CC-BY 4.0; cite model and cycle.
  • HF-radar products: per-operator licence; attribution wording supplied with deployment.
• Reproducibility: TIDE is deterministic given (model cycle, timestamp, bounding box, stride). The drift Monte Carlo is seedable. Figures reproduced with TIDE should record: TIDE version / commit SHA, model cycle timestamps used, parameters (drift object class, ensemble size, seed).

Operational demonstration instance | Request a scientific briefing | Back to overview