FROM SURFACESIGNALSTO SUBSURFACETEMPERATURE

OceanEmbed reconstructs the vertical temperature structure of the North Indian Ocean from surface ocean observations alone.

The model learns the relationship between daily surface ocean conditions and the subsurface temperature field represented by the training target. Evaluation is performed depth by depth and against independent ARGO observations to determine where the reconstruction is reliable and where uncertainty increases.

REGION 5°N–30°N · 45°E–105°EGRID 0.25° × 0.25° · DAILYSTATUS VALIDATED — 2 REGIONAL MODELS
Surface observations to subsurface temperatureA conceptual ocean-data diagram showing surface observations flowing through an embedding into temperature layers at depth.SURFACE OBSERVATIONSDAILY INPUT STATENORTH INDIAN OCEANSSTSSSSSHCURRENTSWINDSOCEAN EMBEDDING0 m50 m100 m200 m500 m1000 mRECONSTRUCTED TEMPERATUREDEPTH-AWARE FIELD

MODEL PIPELINE

A complete workflow from surface data to validated subsurface temperature.

01

SURFACE OBSERVATIONS

Daily SST, SSS, SSH / SLA, currents, and winds define the observed surface state.

SSTSSSSSH+4
02

DATA HARMONIZATION

Input fields are quality-checked and placed on the standardized 0.25° OceanEmbed grid.

REGRIDQCALIGN
03

OCEAN EMBEDDING

The multi-variable surface state is converted into a learned representation.

FEATURE ENCODINGML
04

DEPTH-WISE RECONSTRUCTION

The model reconstructs temperature at multiple depths from the ocean embedding.

0–1000 m15 LEVELS
05

GLORYS REFERENCE

Reconstructed fields are evaluated against the GLORYS reanalysis reference target.

REFERENCEDAILY
06

ARGO VALIDATION

Independent ARGO observations are used to assess real-world consistency.

IN-SITUINDEPENDENT
REGION5°N – 30°N, 45°E – 105°E
GRID0.25° × 0.25°
TEMPORAL RESOLUTIONDaily

WHAT THE MODEL SEES

The model receives surface ocean-state information and reconstructs temperature through the upper ocean and into deeper layers. The two regions’ final models use different surface inputs.

SURFACE INPUT
01SSTBOTH REGIONS
02SSHBOTH REGIONS
03WIND STRESS CURLARABIAN SEA ONLY
04MLDARABIAN SEA ONLY
05SSSARABIAN SEA ONLY
06EDDY VORTICITYARABIAN SEA ONLY

Bay of Bengal’s final model uses SST + SSH with 5-region clustering; Arabian Sea’s adds four more surface fields with 10-region clustering — both with bias correction.

DAILY
SURFACE
STATE
RECONSTRUCTION TARGET
SUBSURFACE
TEMPERATURE
0 m5 m10 m20 m30 m50 m75 m100 m125 m150 m200 m300 m500 m700 m1000 m

EMBEDDING ARCHITECTURE

OceanEmbed converts the multi-variable surface ocean state into a learned representation that can be used to reconstruct temperature at multiple depths.

01INPUT FIELDS
02FEATURE ENCODING
03OCEAN EMBEDDING
04DEPTH-AWARE DECODER
05TEMPERATURE PROFILE
TECHNICAL NOTE Architecture-specific details are reported from the trained model configuration.

HOW THE MODEL IS EVALUATED

Evaluation is performed independently of training, using temperature fields and profiles withheld from the fitting process.

RMSE

Root Mean Square Error

Magnitude of reconstruction error between predicted and reference temperature.

BAY OF BENGAL0.637°C
ARABIAN SEA0.834°C
CORRELATION

Pearson Correlation

How closely predicted temperature variations follow the reference field.

BAY OF BENGAL0.997
ARABIAN SEA0.988
BIAS

Mean Prediction Error

Whether the model systematically overestimates or underestimates temperature.

BAY OF BENGAL-0.385°C
ARABIAN SEA+0.066°C

Avg. of published example predictions (BoB n=3, AS n=2) — not the full validation sample RMSE/Correlation above are drawn from.

PERFORMANCE THROUGH THE WATER COLUMN

Validated RMSE by depth, against withheld ARGO profiles. Error peaks in the thermocline and falls again in deep water for both regions.

0.00.51.01.50m200m500m1000m
BAY OF BENGAL ARABIAN SEA
STANDARD DEPTHS 0 m5 m10 m20 m30 m50 m75 m100 m125 m150 m200 m300 m500 m700 m1000 m

RMSE & CORRELATION BY DEPTH

A depth-selectable readout of validated RMSE and correlation for both regions.

DEPTH SELECTOR
BAY OF BENGAL · 0 m
RMSE0.261°C
CORRELATION0.949
ARABIAN SEA · 0 m
RMSE1.034°C
CORRELATION0.808

INDEPENDENT ARGO VALIDATION

ARGO observations provide an independent reference for assessing whether reconstructed subsurface temperature fields remain physically consistent outside the training target.

MODEL
PREDICTION
+
ARGO
PROFILE
DEPTH-MATCHED
COMPARISON
RMSE / BIAS /
CORRELATION
30°N5°N45°E105°E
BAY OF BENGAL30,019 ARGO MEASUREMENTS
RMSE 0.637°CCORRELATION 0.997
ARABIAN SEA2,129,593 ARGO MEASUREMENTS
RMSE 0.834°CCORRELATION 0.988

WHERE THE MODEL PERFORMS

Regional comparisons distinguish reconstruction behavior across the two proof-of-concept regions.

ACTIVE REGION

BAY OF BENGAL

Final model: SST, SSH · 5-region clustering + bias correction.

RMSE0.637°C
BIAS-0.385°CAVG. OF EXAMPLES
CORRELATION0.997
ARGO VALIDATION COUNT30,019

UNDERSTANDING MODEL ERROR

Reconstruction skill is not uniform with depth or location. Validation against ARGO shows:

01Both regions reconstruct the near-surface layer (0–10 m) most reliably — Bay of Bengal RMSE holds at 0.24–0.26°C, Arabian Sea at 0.62–1.03°C.
02Error peaks in the thermocline, not at depth: Bay of Bengal peaks at 100 m (RMSE 1.464°C), Arabian Sea at 75 m (RMSE 1.351°C) — where vertical gradients are steepest.
03Deep water is easier, not harder, to reconstruct: below 500 m, Bay of Bengal falls to 0.163–0.202°C and Arabian Sea to 0.431–0.540°C.
04Arabian Sea error runs 2–5× higher than Bay of Bengal at nearly every depth — why its model adds four predictors beyond SST/SSH and clusters into 10 regions instead of 5.
05Bay of Bengal runs cold (-0.385°C avg.) and Arabian Sea runs close to neutral (+0.066°C avg.), averaged across the 5 published example predictions on /solution — not yet a full-validation-sample aggregate.

DATA USED FOR EVALUATION

The evaluation design separates the model training target, independent validation, and surface input fields.

ROLEDATASETPURPOSE
MODEL TRAINING TARGETGLORYS Global Ocean ReanalysisReference subsurface temperature field
INDEPENDENT VALIDATIONGridded ARGO / INCOISIndependent in-situ validation
SURFACE INPUTSatellite SSTModel input
SURFACE INPUTSatellite / observation SSSModel input
SURFACE INPUTSatellite / observation SSH / SLAModel input
SURFACE INPUTOcean current productModel input
SURFACE INPUTAtmospheric analysisModel input
OCEANEMBED MODEL STATUS

Two regional models
trained and validated

TRAININGCOMPLETE — 2 REGIONAL MODELS
EVALUATIONCOMPLETE — VS. GLORYS + ARGO
ARGO VALIDATIONCOMPLETE — 2,159,612 MEASUREMENTS
DEPLOYMENT5 VALIDATED PREDICTIONS LIVE ON /SOLUTION