Inquiry about ERA5 wind data representation (temporal, spatial, vertical at 100 m)

Datasets and Usage C3S - Datasets and Usage
1

I am currently conducting research on wind resource assessment using ERA5, particularly focusing on wind speed at 100 m height.

For consistent interpretation across the dataset, I would like to clarify several fundamental characteristics:

  1. Temporal representation
    Are variables such as wind speed provided as instantaneous values or time-averaged values?
    If they are averaged, what is the exact averaging period?

  2. Spatial representation
    Do grid point values represent averages over each grid cell, or values at specific locations (e.g., grid centers)?
    If averaged, how is the spatial averaging performed?

  3. Vertical representation of wind data
    What is the original observational height of wind data assimilated into the model?
    How is wind speed at 100 m height generated from these observations?

             Is it directly constrained by observations, or derived through vertical interpolation or model parameterization?

Understanding these characteristics is essential for assessing the physical reliability of wind speed at turbine hub height.

I would greatly appreciate your guidance.