Conditional Kinematic Interpolant for ERA5 air-parcel tracks
Predicts the acceleration and a scaled velocity score of an air parcel from its state (polar-stereographic x, y and
log-pressure height z = -7 km ln(p/1000 hPa), velocity) and the observed tracks of up to 192 other parcels of its
patch over 48 h (every 3 h), after Jiang, Marzouk, Bose & Pooladian, Learning smooth dynamics via Kinematic
Interpolants, arXiv:2610.22519. Integrated forward (forecast) or backward (backcast) up to 24 h, deterministically
or as a stochastic ensemble (ensemble.json: eps_rel 1.5, chosen so that the 24-h spread matches the error of the
ensemble mean on validation patches).
- Training data: LAGRANTO tracks in hourly ERA5 (0.25ยฐ, 37 pressure levels), releases every 5 days of 2015-2017, 20 start levels, 16 patches of 480 parcels per level, both hemispheres (southern mirrored); 2.5e7 training tracks.
- Test (2021, unseen year): median 24-h error of the deterministic forecast 335 km, backcast 254 km; about 45 % below straight motion at 12-24 h.
context_ki_era5.pt: EMA weights, training arguments (args, widthd_model512) and the per-axis scales (scales, also inscales.json). Code: github.com/yanxingjianken/ki-lagrangian-tracks (03_era5).
In-browser graphs (onnx/)
encoder.int8.onnx (context tokens (1, 3264, 8) -> latents) and decoder.int8.onnx (latents, queries (1, Q, 8) ->
acceleration and scaled score) with the weights of the matrix products stored as 8-bit integers per output channel;
config.json holds the scales, the ensemble settings and the token layout. On 2021 tracks their 24-h ensemble-mean
errors match the full-precision model within the scatter between sets of random kicks. Used by the page
yanxingjianken.github.io/blocking-plots/rwb-prediction/ with onnxruntime-web.