CMEMS L4 — Blended Wind Product

What This Dataset Is

The CMEMS Level-4 (L4) wind product is a multi-satellite, observation-based blended wind field. It merges data from multiple scatterometer satellites and applies objective interpolation to produce a spatially complete, gridded wind dataset.

It is not a forecast and not a free-running atmospheric model.

How It Works

1. Collect wind observations from multiple scatterometers (e.g., ASCAT A/B/C).
2. Apply cross-satellite bias harmonization.
3. Merge overlapping observations.
4. Use objective interpolation (optimal interpolation techniques) to fill spatial and temporal gaps.
5. Produce a continuous hourly gridded wind field.

Strengths

• Observation-driven
• Multi-satellite support improves coverage
• Reduced orbit-time sampling bias
• Hourly resolution available
• Spatially continuous field
• Suitable for global mapping

Limitations

• Includes interpolation (not raw measurements everywhere)
• Slight smoothing of sharp gradients
• Extreme winds may be damped
• Directional distributions may be broadened by interpolation
• Not dynamically consistent with full atmospheric state

Appropriate Uses

• Marine mapping applications
• Wind climatology visualization
• General environmental monitoring
• User-facing wind products requiring completeness

Not Recommended For

• Operational marine navigation
• Storm intensity assessment
• Engineering design calculations
• Safety-critical planning